620781157 has 2 divisors, whose sum is σ = 620781158. Its totient is φ = 620781156.

The previous prime is 620781149. The next prime is 620781179. The reversal of 620781157 is 751187026.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 318229921 + 302551236 = 17839^2 + 17394^2 .

It is a cyclic number.

It is not a de Polignac number, because 620781157 - 2³ = 620781149 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (620781127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 310390578 + 310390579.

It is an arithmetic number, because the mean of its divisors is an integer number (310390579).

Almost surely, 2^620781157 is an apocalyptic number.

It is an amenable number.

620781157 is a deficient number, since it is larger than the sum of its proper divisors (1).

620781157 is an equidigital number, since it uses as much as digits as its factorization.

620781157 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23520, while the sum is 37.

The square root of 620781157 is about 24915.4802682991. The cubic root of 620781157 is about 853.0598631176.

The spelling of 620781157 in words is "six hundred twenty million, seven hundred eighty-one thousand, one hundred fifty-seven".