87491137 has 2 divisors, whose sum is σ = 87491138. Its totient is φ = 87491136.

The previous prime is 87491123. The next prime is 87491153. The reversal of 87491137 is 73119478.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 85303696 + 2187441 = 9236^2 + 1479^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-87491137 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 87491137.

It is not a weakly prime, because it can be changed into another prime (87491177) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43745568 + 43745569.

It is an arithmetic number, because the mean of its divisors is an integer number (43745569).

Almost surely, 2^87491137 is an apocalyptic number.

It is an amenable number.

87491137 is a deficient number, since it is larger than the sum of its proper divisors (1).

87491137 is an equidigital number, since it uses as much as digits as its factorization.

87491137 is an evil number, because the sum of its binary digits is even.

The product of its digits is 42336, while the sum is 40.

The square root of 87491137 is about 9353.6697076602. The cubic root of 87491137 is about 443.9370108544.

The spelling of 87491137 in words is "eighty-seven million, four hundred ninety-one thousand, one hundred thirty-seven".