61661560 has 16 divisors (see below), whose sum is σ = 138738600. Its totient is φ = 24664608.

The previous prime is 61661539. The next prime is 61661617. The reversal of 61661560 is 6516616.

It is a super-3 number, since 3×61661560³ (a number of 24 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 770730 + ... + 770809.

Almost surely, 2^61661560 is an apocalyptic number.

It is an amenable number.

61661560 is an abundant number, since it is smaller than the sum of its proper divisors (77077040).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61661560 is a wasteful number, since it uses less digits than its factorization.

61661560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1541550 (or 1541546 counting only the distinct ones).

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 61661560 is about 7852.4875039697. The cubic root of 61661560 is about 395.0676805461.

The spelling of 61661560 in words is "sixty-one million, six hundred sixty-one thousand, five hundred sixty".