51626781 has 32 divisors (see below), whose sum is σ = 81148800. Its totient is φ = 32348160.

The previous prime is 51626767. The next prime is 51626797. The reversal of 51626781 is 18762615.

51626781 is a `hidden beast` number, since 516 + 2 + 67 + 81 = 666.

51626781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 51626781 - 2⁹ = 51626269 is a prime.

It is a super-2 number, since 2×51626781² = 5330649032843922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51626741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 80221 + ... + 80861.

It is an arithmetic number, because the mean of its divisors is an integer number (2535900).

Almost surely, 2^51626781 is an apocalyptic number.

It is an amenable number.

51626781 is a deficient number, since it is larger than the sum of its proper divisors (29522019).

51626781 is a wasteful number, since it uses less digits than its factorization.

51626781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 826 (or 820 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 51626781 is about 7185.1778683621. The cubic root of 51626781 is about 372.3559937624.

The spelling of 51626781 in words is "fifty-one million, six hundred twenty-six thousand, seven hundred eighty-one".