157238821 has 2 divisors, whose sum is σ = 157238822. Its totient is φ = 157238820.

The previous prime is 157238803. The next prime is 157238849. The reversal of 157238821 is 128832751.

157238821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 146676321 + 10562500 = 12111^2 + 3250^2 .

It is a cyclic number.

It is not a de Polignac number, because 157238821 - 2⁷ = 157238693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (157238891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78619410 + 78619411.

It is an arithmetic number, because the mean of its divisors is an integer number (78619411).

Almost surely, 2^157238821 is an apocalyptic number.

It is an amenable number.

157238821 is a deficient number, since it is larger than the sum of its proper divisors (1).

157238821 is an equidigital number, since it uses as much as digits as its factorization.

157238821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 26880, while the sum is 37.

The square root of 157238821 is about 12539.4904601423. The cubic root of 157238821 is about 539.7424709382.

The spelling of 157238821 in words is "one hundred fifty-seven million, two hundred thirty-eight thousand, eight hundred twenty-one".