991002377 has 4 divisors (see below), whose sum is σ = 991165956. Its totient is φ = 990838800.

The previous prime is 991002367. The next prime is 991002407. The reversal of 991002377 is 773200199.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 706709056 + 284293321 = 26584^2 + 16861^2 .

It is a cyclic number.

It is not a de Polignac number, because 991002377 - 2²⁰ = 989953801 is a prime.

It is a super-2 number, since 2×991002377² = 1964171422439300258, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 991002377.

It is not an unprimeable number, because it can be changed into a prime (991002317) 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, 72338 + ... + 84939.

It is an arithmetic number, because the mean of its divisors is an integer number (247791489).

Almost surely, 2^991002377 is an apocalyptic number.

It is an amenable number.

991002377 is a deficient number, since it is larger than the sum of its proper divisors (163579).

991002377 is a wasteful number, since it uses less digits than its factorization.

991002377 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163578.

The product of its (nonzero) digits is 23814, while the sum is 38.

The square root of 991002377 is about 31480.1902313185. The cubic root of 991002377 is about 996.9917518508.

The spelling of 991002377 in words is "nine hundred ninety-one million, two thousand, three hundred seventy-seven".