51709986 has 12 divisors (see below), whose sum is σ = 112038342. Its totient is φ = 17236656.

The previous prime is 51709967. The next prime is 51709993. The reversal of 51709986 is 68990715.

It can be written as a sum of positive squares in only one way, i.e., 48734361 + 2975625 = 6981^2 + 1725^2 .

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1436371 + ... + 1436406.

Almost surely, 2^51709986 is an apocalyptic number.

51709986 is an abundant number, since it is smaller than the sum of its proper divisors (60328356).

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

51709986 is a wasteful number, since it uses less digits than its factorization.

51709986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2872785 (or 2872782 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The square root of 51709986 is about 7190.9655818951. The cubic root of 51709986 is about 372.5559239190. Note that the first 3 decimals are identical.

The spelling of 51709986 in words is "fifty-one million, seven hundred nine thousand, nine hundred eighty-six".