51661025 has 24 divisors (see below), whose sum is σ = 70688184. Its totient is φ = 37209600.

The previous prime is 51661003. The next prime is 51661063. The reversal of 51661025 is 52016615.

It can be written as a sum of positive squares in 12 ways, for example, as 42667024 + 8994001 = 6532^2 + 2999^2 .

It is not a de Polignac number, because 51661025 - 2¹⁸ = 51398881 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 51660985 and 51661003.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11387 + ... + 15263.

It is an arithmetic number, because the mean of its divisors is an integer number (2945341).

Almost surely, 2^51661025 is an apocalyptic number.

It is an amenable number.

51661025 is a deficient number, since it is larger than the sum of its proper divisors (19027159).

51661025 is a wasteful number, since it uses less digits than its factorization.

51661025 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3941 (or 3936 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 26.

The square root of 51661025 is about 7187.5604345285. The cubic root of 51661025 is about 372.4383033713.

The spelling of 51661025 in words is "fifty-one million, six hundred sixty-one thousand, twenty-five".