356640991 has 4 divisors (see below), whose sum is σ = 407589712. Its totient is φ = 305692272.

The previous prime is 356640971. The next prime is 356641027. The reversal of 356640991 is 199046653.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199046653 = 13 ⋅15311281.

It is a cyclic number.

It is not a de Polignac number, because 356640991 - 2⁵ = 356640959 is a prime.

It is a super-2 number, since 2×356640991² = 254385592922924162, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (356640901) 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, 25474350 + ... + 25474363.

It is an arithmetic number, because the mean of its divisors is an integer number (101897428).

Almost surely, 2^356640991 is an apocalyptic number.

356640991 is a deficient number, since it is larger than the sum of its proper divisors (50948721).

356640991 is an equidigital number, since it uses as much as digits as its factorization.

356640991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50948720.

The product of its (nonzero) digits is 174960, while the sum is 43.

The square root of 356640991 is about 18884.9408524358. The cubic root of 356640991 is about 709.1592183217.

The spelling of 356640991 in words is "three hundred fifty-six million, six hundred forty thousand, nine hundred ninety-one".