157218401 has 2 divisors, whose sum is σ = 157218402. Its totient is φ = 157218400.

The previous prime is 157218389. The next prime is 157218443. The reversal of 157218401 is 104812751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120978001 + 36240400 = 10999^2 + 6020^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157218401 is a prime.

It is a super-2 number, since 2×157218401² = 49435251225993602, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (157218461) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78609200 + 78609201.

It is an arithmetic number, because the mean of its divisors is an integer number (78609201).

Almost surely, 2^157218401 is an apocalyptic number.

It is an amenable number.

157218401 is a deficient number, since it is larger than the sum of its proper divisors (1).

157218401 is an equidigital number, since it uses as much as digits as its factorization.

157218401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2240, while the sum is 29.

The square root of 157218401 is about 12538.6762060434. The cubic root of 157218401 is about 539.7191051681.

The spelling of 157218401 in words is "one hundred fifty-seven million, two hundred eighteen thousand, four hundred one".