61775581 has 16 divisors (see below), whose sum is σ = 72316800. Its totient is φ = 51674688.

The previous prime is 61775521. The next prime is 61775599. The reversal of 61775581 is 18557716.

It is a cyclic number.

It is not a de Polignac number, because 61775581 - 2⁷ = 61775453 is a prime.

It is a super-2 number, since 2×61775581² = 7632444815775122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61775521) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 99490 + ... + 100108.

It is an arithmetic number, because the mean of its divisors is an integer number (4519800).

Almost surely, 2^61775581 is an apocalyptic number.

It is an amenable number.

61775581 is a deficient number, since it is larger than the sum of its proper divisors (10541219).

61775581 is a wasteful number, since it uses less digits than its factorization.

61775581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 948.

The product of its digits is 58800, while the sum is 40.

The square root of 61775581 is about 7859.7443342643. The cubic root of 61775581 is about 395.3110427261.

The spelling of 61775581 in words is "sixty-one million, seven hundred seventy-five thousand, five hundred eighty-one".