61551565 has 16 divisors (see below), whose sum is σ = 77366016. Its totient is φ = 46921600.

The previous prime is 61551559. The next prime is 61551587. The reversal of 61551565 is 56515516.

It is not a de Polignac number, because 61551565 - 2⁷ = 61551437 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61551565.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 34905 + ... + 36625.

It is an arithmetic number, because the mean of its divisors is an integer number (4835376).

Almost surely, 2^61551565 is an apocalyptic number.

It is an amenable number.

61551565 is a deficient number, since it is larger than the sum of its proper divisors (15814451).

61551565 is a wasteful number, since it uses less digits than its factorization.

61551565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2060.

The product of its digits is 22500, while the sum is 34.

The square root of 61551565 is about 7845.4805461488. The cubic root of 61551565 is about 394.8326268405.

The spelling of 61551565 in words is "sixty-one million, five hundred fifty-one thousand, five hundred sixty-five".