51215136 has 48 divisors (see below), whose sum is σ = 153647424. Its totient is φ = 14632704.

The previous prime is 51215117. The next prime is 51215137. The reversal of 51215136 is 63151215.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (51215137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37435 + ... + 38778.

It is an arithmetic number, because the mean of its divisors is an integer number (3200988).

Almost surely, 2^51215136 is an apocalyptic number.

51215136 is a gapful number since it is divisible by the number (56) formed by its first and last digit.

It is an amenable number.

51215136 is an abundant number, since it is smaller than the sum of its proper divisors (102432288).

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

51215136 is a wasteful number, since it uses less digits than its factorization.

51215136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76233 (or 76225 counting only the distinct ones).

The product of its digits is 900, while the sum is 24.

The square root of 51215136 is about 7156.4751099965. The cubic root of 51215136 is about 371.3636942758.

The spelling of 51215136 in words is "fifty-one million, two hundred fifteen thousand, one hundred thirty-six".