87981013 has 2 divisors, whose sum is σ = 87981014. Its totient is φ = 87981012.

The previous prime is 87980969. The next prime is 87981059. The reversal of 87981013 is 31018978.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 86545809 + 1435204 = 9303^2 + 1198^2 .

It is a cyclic number.

It is not a de Polignac number, because 87981013 - 2¹⁷ = 87849941 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (87921013) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43990506 + 43990507.

It is an arithmetic number, because the mean of its divisors is an integer number (43990507).

Almost surely, 2^87981013 is an apocalyptic number.

It is an amenable number.

87981013 is a deficient number, since it is larger than the sum of its proper divisors (1).

87981013 is an equidigital number, since it uses as much as digits as its factorization.

87981013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12096, while the sum is 37.

The square root of 87981013 is about 9379.8194545524. The cubic root of 87981013 is about 444.7640258811.

The spelling of 87981013 in words is "eighty-seven million, nine hundred eighty-one thousand, thirteen".