61908521 has 6 divisors (see below), whose sum is σ = 62797866. Its totient is φ = 61031600.

The previous prime is 61908499. The next prime is 61908589. The reversal of 61908521 is 12580916.

It can be written as a sum of positive squares in only one way, i.e., 59892121 + 2016400 = 7739^2 + 1420^2 .

It is a de Polignac number, because none of the positive numbers 2^k-61908521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61938521) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1100 + ... + 11181.

It is an arithmetic number, because the mean of its divisors is an integer number (10466311).

Almost surely, 2^61908521 is an apocalyptic number.

It is an amenable number.

61908521 is a deficient number, since it is larger than the sum of its proper divisors (889345).

61908521 is an equidigital number, since it uses as much as digits as its factorization.

61908521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12423 (or 12352 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 32.

The square root of 61908521 is about 7868.1968074013. The cubic root of 61908521 is about 395.5944071057.

The spelling of 61908521 in words is "sixty-one million, nine hundred eight thousand, five hundred twenty-one".