61641864 has 64 divisors (see below), whose sum is σ = 181310400. Its totient is φ = 19337472.

The previous prime is 61641821. The next prime is 61641887. The reversal of 61641864 is 46814616.

61641864 is a `hidden beast` number, since 6 + 1 + 641 + 8 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4722 + ... + 12065.

It is an arithmetic number, because the mean of its divisors is an integer number (2832975).

Almost surely, 2^61641864 is an apocalyptic number.

It is an amenable number.

61641864 is an abundant number, since it is smaller than the sum of its proper divisors (119668536).

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

61641864 is a wasteful number, since it uses less digits than its factorization.

61641864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16819 (or 16809 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 61641864 is about 7851.2332789187. The cubic root of 61641864 is about 395.0256117560.

The spelling of 61641864 in words is "sixty-one million, six hundred forty-one thousand, eight hundred sixty-four".