157217987 has 2 divisors, whose sum is σ = 157217988. Its totient is φ = 157217986.

The previous prime is 157217941. The next prime is 157218011. The reversal of 157217987 is 789712751.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157217987 is a prime.

It is not a weakly prime, because it can be changed into another prime (157217087) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78608993 + 78608994.

It is an arithmetic number, because the mean of its divisors is an integer number (78608994).

Almost surely, 2^157217987 is an apocalyptic number.

157217987 is a deficient number, since it is larger than the sum of its proper divisors (1).

157217987 is an equidigital number, since it uses as much as digits as its factorization.

157217987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 246960, while the sum is 47.

The square root of 157217987 is about 12538.6596971128. The cubic root of 157217987 is about 539.7186314239.

The spelling of 157217987 in words is "one hundred fifty-seven million, two hundred seventeen thousand, nine hundred eighty-seven".