61521334191900 has 216 divisors, whose sum is σ = 210375070633728. Its totient is φ = 14913596880000.

The previous prime is 61521334191839. The next prime is 61521334191971. The reversal of 61521334191900 is 919143312516.

61521334191900 is a `hidden beast` number, since 6 + 1 + 5 + 213 + 3 + 419 + 19 + 0 + 0 = 666.

61521334191900 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×61521334191900² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 243126445 + ... + 243379355.

Almost surely, 2^{61521334191900} is an apocalyptic number.

61521334191900 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61521334191900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105187535316864).

61521334191900 is an abundant number, since it is smaller than the sum of its proper divisors (148853736441828).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61521334191900 is a wasteful number, since it uses less digits than its factorization.

61521334191900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 277513 (or 277503 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The spelling of 61521334191900 in words is "sixty-one trillion, five hundred twenty-one billion, three hundred thirty-four million, one hundred ninety-one thousand, nine hundred".