51121656 has 24 divisors (see below), whose sum is σ = 138454680. Its totient is φ = 17040528.

The previous prime is 51121649. The next prime is 51121657. The reversal of 51121656 is 65612115.

It is a happy number.

51121656 is a `hidden beast` number, since 5 + 1 + 1 + 2 + 1 + 656 = 666.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×51121656² = 5226847424364672, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51121657) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 354940 + ... + 355083.

It is an arithmetic number, because the mean of its divisors is an integer number (5768945).

Almost surely, 2^51121656 is an apocalyptic number.

It is an amenable number.

51121656 is an abundant number, since it is smaller than the sum of its proper divisors (87333024).

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

51121656 is a wasteful number, since it uses less digits than its factorization.

51121656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 710035 (or 710028 counting only the distinct ones).

The product of its digits is 1800, while the sum is 27.

The square root of 51121656 is about 7149.9409787774. The cubic root of 51121656 is about 371.1376138405.

The spelling of 51121656 in words is "fifty-one million, one hundred twenty-one thousand, six hundred fifty-six".