61307661 has 32 divisors (see below), whose sum is σ = 91929600. Its totient is φ = 36115200.

The previous prime is 61307657. The next prime is 61307671. The reversal of 61307661 is 16670316.

It is not a de Polignac number, because 61307661 - 2² = 61307657 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61307611) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 146110 + ... + 146528.

It is an arithmetic number, because the mean of its divisors is an integer number (2872800).

Almost surely, 2^61307661 is an apocalyptic number.

It is an amenable number.

61307661 is a deficient number, since it is larger than the sum of its proper divisors (30621939).

61307661 is a wasteful number, since it uses less digits than its factorization.

61307661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609.

The product of its (nonzero) digits is 4536, while the sum is 30.

The square root of 61307661 is about 7829.9208808263. The cubic root of 61307661 is about 394.3104157005.

Adding to 61307661 its reverse (16670316), we get a palindrome (77977977).

The spelling of 61307661 in words is "sixty-one million, three hundred seven thousand, six hundred sixty-one".