157620121 has 2 divisors, whose sum is σ = 157620122. Its totient is φ = 157620120.

The previous prime is 157620119. The next prime is 157620131. The reversal of 157620121 is 121026751.

157620121 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., 155251600 + 2368521 = 12460^2 + 1539^2 .

It is a cyclic number.

It is not a de Polignac number, because 157620121 - 2¹ = 157620119 is a prime.

Together with 157620119, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (157620131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 78810060 + 78810061.

It is an arithmetic number, because the mean of its divisors is an integer number (78810061).

Almost surely, 2^157620121 is an apocalyptic number.

It is an amenable number.

157620121 is a deficient number, since it is larger than the sum of its proper divisors (1).

157620121 is an equidigital number, since it uses as much as digits as its factorization.

157620121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840, while the sum is 25.

The square root of 157620121 is about 12554.6852210639. The cubic root of 157620121 is about 540.1784058435.

Adding to 157620121 its reverse (121026751), we get a palindrome (278646872).

The spelling of 157620121 in words is "one hundred fifty-seven million, six hundred twenty thousand, one hundred twenty-one".