51213136 has 20 divisors (see below), whose sum is σ = 106858612. Its totient is φ = 23636736.

The previous prime is 51213119. The next prime is 51213137. The reversal of 51213136 is 63131215.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 5569600 + 45643536 = 2360^2 + 6756^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51213137) 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, 122901 + ... + 123316.

Almost surely, 2^51213136 is an apocalyptic number.

It is an amenable number.

51213136 is an abundant number, since it is smaller than the sum of its proper divisors (55645476).

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

51213136 is a wasteful number, since it uses less digits than its factorization.

51213136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 246238 (or 246232 counting only the distinct ones).

The product of its digits is 540, while the sum is 22.

The square root of 51213136 is about 7156.3353750366. The cubic root of 51213136 is about 371.3588601772.

The spelling of 51213136 in words is "fifty-one million, two hundred thirteen thousand, one hundred thirty-six".