51969645 has 120 divisors (see below), whose sum is σ = 116230296. Its totient is φ = 21337344.

The previous prime is 51969637. The next prime is 51969661. The reversal of 51969645 is 54696915.

It is a happy number.

51969645 is a `hidden beast` number, since 519 + 6 + 96 + 45 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 6245001 + 45724644 = 2499^2 + 6762^2 .

It is not a de Polignac number, because 51969645 - 2³ = 51969637 is a prime.

It is a super-3 number, since 3×51969645³ (a number of 24 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 51969645.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 1404567 + ... + 1404603.

Almost surely, 2^51969645 is an apocalyptic number.

It is an amenable number.

51969645 is an abundant number, since it is smaller than the sum of its proper divisors (64260651).

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

51969645 is a wasteful number, since it uses less digits than its factorization.

51969645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89 (or 65 counting only the distinct ones).

The product of its digits is 291600, while the sum is 45.

The square root of 51969645 is about 7208.9975031207. The cubic root of 51969645 is about 373.1784730986.

It can be divided in two parts, 5196 and 9645, that added together give a palindrome (14841).

The spelling of 51969645 in words is "fifty-one million, nine hundred sixty-nine thousand, six hundred forty-five".