621831157 has 4 divisors (see below), whose sum is σ = 627536140. Its totient is φ = 616126176.

The previous prime is 621831131. The next prime is 621831167. The reversal of 621831157 is 751138126.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 751138126 = 2 ⋅375569063.

It can be written as a sum of positive squares in 2 ways, for example, as 510127396 + 111703761 = 22586^2 + 10569^2 .

It is a cyclic number.

It is not a de Polignac number, because 621831157 - 2²⁷ = 487613429 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (621831167) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2852328 + ... + 2852545.

It is an arithmetic number, because the mean of its divisors is an integer number (156884035).

Almost surely, 2^621831157 is an apocalyptic number.

It is an amenable number.

621831157 is a deficient number, since it is larger than the sum of its proper divisors (5704983).

621831157 is a wasteful number, since it uses less digits than its factorization.

621831157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5704982.

The product of its digits is 10080, while the sum is 34.

The square root of 621831157 is about 24936.5426031758. The cubic root of 621831157 is about 853.5405522795.

The spelling of 621831157 in words is "six hundred twenty-one million, eight hundred thirty-one thousand, one hundred fifty-seven".