61521636 has 24 divisors (see below), whose sum is σ = 156600864. Its totient is φ = 18642880.

The previous prime is 61521617. The next prime is 61521641. The reversal of 61521636 is 63612516.

It is a super-2 number, since 2×61521636² = 7569823392232992, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 232905 + ... + 233168.

It is an arithmetic number, because the mean of its divisors is an integer number (6525036).

Almost surely, 2^61521636 is an apocalyptic number.

61521636 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

61521636 is an abundant number, since it is smaller than the sum of its proper divisors (95079228).

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

61521636 is a wasteful number, since it uses less digits than its factorization.

61521636 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 466091 (or 466089 counting only the distinct ones).

The product of its digits is 6480, while the sum is 30.

The square root of 61521636 is about 7843.5729103515. The cubic root of 61521636 is about 394.7686216360.

The spelling of 61521636 in words is "sixty-one million, five hundred twenty-one thousand, six hundred thirty-six".