61521502100 has 72 divisors (see below), whose sum is σ = 137761370208. Its totient is φ = 23829724800.

The previous prime is 61521502061. The next prime is 61521502109. The reversal of 61521502100 is 120512516.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61521502109) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 741299 + ... + 820101.

It is an arithmetic number, because the mean of its divisors is an integer number (1913352364).

Almost surely, 2^61521502100 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61521502100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68880685104).

61521502100 is an abundant number, since it is smaller than the sum of its proper divisors (76239868108).

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

61521502100 is a wasteful number, since it uses less digits than its factorization.

61521502100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79065 (or 79058 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The spelling of 61521502100 in words is "sixty-one billion, five hundred twenty-one million, five hundred two thousand, one hundred".