52157981 has 2 divisors, whose sum is σ = 52157982. Its totient is φ = 52157980.

The previous prime is 52157969. The next prime is 52157993. The reversal of 52157981 is 18975125.

It is a balanced prime because it is at equal distance from previous prime (52157969) and next prime (52157993).

It can be written as a sum of positive squares in only one way, i.e., 30349081 + 21808900 = 5509^2 + 4670^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-52157981 is a prime.

It is a super-2 number, since 2×52157981² = 5440909963992722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (52157081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 26078990 + 26078991.

It is an arithmetic number, because the mean of its divisors is an integer number (26078991).

Almost surely, 2^52157981 is an apocalyptic number.

It is an amenable number.

52157981 is a deficient number, since it is larger than the sum of its proper divisors (1).

52157981 is an equidigital number, since it uses as much as digits as its factorization.

52157981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 25200, while the sum is 38.

The square root of 52157981 is about 7222.0482551697. The cubic root of 52157981 is about 373.6287244619.

The spelling of 52157981 in words is "fifty-two million, one hundred fifty-seven thousand, nine hundred eighty-one".