61437521520 has 100 divisors (see below), whose sum is σ = 213381636600. Its totient is φ = 16383337344.

The previous prime is 61437521513. The next prime is 61437521521. The reversal of 61437521520 is 2512573416.

61437521520 is a `hidden beast` number, since 6 + 1 + 43 + 75 + 21 + 520 = 666.

It is a super-2 number, since 2×61437521520² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61437521521) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 4734070 + ... + 4747029.

It is an arithmetic number, because the mean of its divisors is an integer number (2133816366).

Almost surely, 2^61437521520 is an apocalyptic number.

61437521520 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

61437521520 is an abundant number, since it is smaller than the sum of its proper divisors (151944115080).

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

61437521520 is a wasteful number, since it uses less digits than its factorization.

61437521520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9481124 (or 9481109 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The spelling of 61437521520 in words is "sixty-one billion, four hundred thirty-seven million, five hundred twenty-one thousand, five hundred twenty".