51620725 has 24 divisors (see below), whose sum is σ = 71323560. Its totient is φ = 36798720.

The previous prime is 51620669. The next prime is 51620729. The reversal of 51620725 is 52702615.

It can be written as a sum of positive squares in 12 ways, for example, as 5692996 + 45927729 = 2386^2 + 6777^2 .

It is not a de Polignac number, because 51620725 - 2¹⁵ = 51587957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 51620693 and 51620702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51620729) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6687 + ... + 12163.

It is an arithmetic number, because the mean of its divisors is an integer number (2971815).

Almost surely, 2^51620725 is an apocalyptic number.

It is an amenable number.

51620725 is a deficient number, since it is larger than the sum of its proper divisors (19702835).

51620725 is a wasteful number, since it uses less digits than its factorization.

51620725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5529 (or 5524 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 28.

The square root of 51620725 is about 7184.7564328932. The cubic root of 51620725 is about 372.3414336444.

The spelling of 51620725 in words is "fifty-one million, six hundred twenty thousand, seven hundred twenty-five".