61685664 has 48 divisors (see below), whose sum is σ = 162515808. Its totient is φ = 20486912.

The previous prime is 61685653. The next prime is 61685671. The reversal of 61685664 is 46658616.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×61685664² = 7610242286241792, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29419 + ... + 31445.

It is an arithmetic number, because the mean of its divisors is an integer number (3385746).

Almost surely, 2^61685664 is an apocalyptic number.

It is an amenable number.

61685664 is an abundant number, since it is smaller than the sum of its proper divisors (100830144).

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

61685664 is a wasteful number, since it uses less digits than its factorization.

61685664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2357 (or 2349 counting only the distinct ones).

The product of its digits is 207360, while the sum is 42.

The square root of 61685664 is about 7854.0221542850. The cubic root of 61685664 is about 395.1191522183.

The spelling of 61685664 in words is "sixty-one million, six hundred eighty-five thousand, six hundred sixty-four".