157616821 has 2 divisors, whose sum is σ = 157616822. Its totient is φ = 157616820.

The previous prime is 157616813. The next prime is 157616831. The reversal of 157616821 is 128616751.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 140896900 + 16719921 = 11870^2 + 4089^2 .

It is a cyclic number.

It is not a de Polignac number, because 157616821 - 2³ = 157616813 is a prime.

It is a nialpdrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (157616831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78808410 + 78808411.

It is an arithmetic number, because the mean of its divisors is an integer number (78808411).

Almost surely, 2^157616821 is an apocalyptic number.

It is an amenable number.

157616821 is a deficient number, since it is larger than the sum of its proper divisors (1).

157616821 is an equidigital number, since it uses as much as digits as its factorization.

157616821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 20160, while the sum is 37.

The square root of 157616821 is about 12554.5537953366. The cubic root of 157616821 is about 540.1746360178.

The spelling of 157616821 in words is "one hundred fifty-seven million, six hundred sixteen thousand, eight hundred twenty-one".