51580981 has 2 divisors, whose sum is σ = 51580982. Its totient is φ = 51580980.

The previous prime is 51580957. The next prime is 51581017. The reversal of 51580981 is 18908515.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 37638225 + 13942756 = 6135^2 + 3734^2 .

It is a cyclic number.

It is not a de Polignac number, because 51580981 - 2⁷ = 51580853 is a prime.

It is a super-2 number, since 2×51580981² = 5321195201844722, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51580981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (51580901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25790490 + 25790491.

It is an arithmetic number, because the mean of its divisors is an integer number (25790491).

Almost surely, 2^51580981 is an apocalyptic number.

It is an amenable number.

51580981 is a deficient number, since it is larger than the sum of its proper divisors (1).

51580981 is an equidigital number, since it uses as much as digits as its factorization.

51580981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14400, while the sum is 37.

The square root of 51580981 is about 7181.9900445489. The cubic root of 51580981 is about 372.2458509921.

The spelling of 51580981 in words is "fifty-one million, five hundred eighty thousand, nine hundred eighty-one".