157798321 has 2 divisors, whose sum is σ = 157798322. Its totient is φ = 157798320.

The previous prime is 157798283. The next prime is 157798327. The reversal of 157798321 is 123897751.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 157778721 + 19600 = 12561^2 + 140^2 .

It is a cyclic number.

It is not a de Polignac number, because 157798321 - 2²⁷ = 23580593 is a prime.

It is a super-2 number, since 2×157798321² = 49800620220838082, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (157798327) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78899160 + 78899161.

It is an arithmetic number, because the mean of its divisors is an integer number (78899161).

Almost surely, 2^157798321 is an apocalyptic number.

It is an amenable number.

157798321 is a deficient number, since it is larger than the sum of its proper divisors (1).

157798321 is an equidigital number, since it uses as much as digits as its factorization.

157798321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 105840, while the sum is 43.

The square root of 157798321 is about 12561.7801684315. The cubic root of 157798321 is about 540.3818983462.

The spelling of 157798321 in words is "one hundred fifty-seven million, seven hundred ninety-eight thousand, three hundred twenty-one".