61902509 has 2 divisors, whose sum is σ = 61902510. Its totient is φ = 61902508.

The previous prime is 61902493. The next prime is 61902523. The reversal of 61902509 is 90520916.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 34633225 + 27269284 = 5885^2 + 5222^2 .

It is a cyclic number.

It is not a de Polignac number, because 61902509 - 2⁴ = 61902493 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61902409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30951254 + 30951255.

It is an arithmetic number, because the mean of its divisors is an integer number (30951255).

Almost surely, 2^61902509 is an apocalyptic number.

It is an amenable number.

61902509 is a deficient number, since it is larger than the sum of its proper divisors (1).

61902509 is an equidigital number, since it uses as much as digits as its factorization.

61902509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4860, while the sum is 32.

The square root of 61902509 is about 7867.8147537928. The cubic root of 61902509 is about 395.5816011649.

The spelling of 61902509 in words is "sixty-one million, nine hundred two thousand, five hundred nine".