51057621 has 30 divisors (see below), whose sum is σ = 78013782. Its totient is φ = 33274800.

The previous prime is 51057607. The next prime is 51057637. The reversal of 51057621 is 12675015.

51057621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 50552100 + 505521 = 7110^2 + 711^2 .

It is not a de Polignac number, because 51057621 - 2¹³ = 51049429 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51057691) 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 29 ways as a sum of consecutive naturals, for example, 505471 + ... + 505571.

Almost surely, 2^51057621 is an apocalyptic number.

It is an amenable number.

51057621 is a deficient number, since it is larger than the sum of its proper divisors (26956161).

51057621 is an equidigital number, since it uses as much as digits as its factorization.

51057621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 271 (or 183 counting only the distinct ones).

The product of its (nonzero) digits is 2100, while the sum is 27.

The square root of 51057621 is about 7145.4615666170. The cubic root of 51057621 is about 370.9825867353.

The spelling of 51057621 in words is "fifty-one million, fifty-seven thousand, six hundred twenty-one".