51620687 has 4 divisors (see below), whose sum is σ = 54657216. Its totient is φ = 48584160.

The previous prime is 51620669. The next prime is 51620729. The reversal of 51620687 is 78602615.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 51620687 - 2⁸ = 51620431 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51620287) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1518239 + ... + 1518272.

It is an arithmetic number, because the mean of its divisors is an integer number (13664304).

Almost surely, 2^51620687 is an apocalyptic number.

51620687 is a deficient number, since it is larger than the sum of its proper divisors (3036529).

51620687 is a wasteful number, since it uses less digits than its factorization.

51620687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3036528.

The product of its (nonzero) digits is 20160, while the sum is 35.

The square root of 51620687 is about 7184.7537884050. The cubic root of 51620687 is about 372.3413422794.

The spelling of 51620687 in words is "fifty-one million, six hundred twenty thousand, six hundred eighty-seven".