51642690 has 32 divisors (see below), whose sum is σ = 135210816. Its totient is φ = 12519360.

The previous prime is 51642677. The next prime is 51642691. The reversal of 51642690 is 9624615.

It is a super-2 number, since 2×51642690² = 5333934860872200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (51642691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 77917 + ... + 78576.

It is an arithmetic number, because the mean of its divisors is an integer number (4225338).

Almost surely, 2^51642690 is an apocalyptic number.

51642690 is an abundant number, since it is smaller than the sum of its proper divisors (83568126).

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

51642690 is a wasteful number, since it uses less digits than its factorization.

51642690 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 156514.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 51642690 is about 7186.2848538031. The cubic root of 51642690 is about 372.3942374996.

The spelling of 51642690 in words is "fifty-one million, six hundred forty-two thousand, six hundred ninety".