991890495 has 32 divisors (see below), whose sum is σ = 1796644800. Its totient is φ = 519023232.

The previous prime is 991890481. The next prime is 991890547. The reversal of 991890495 is 594098199.

It is not a de Polignac number, because 991890495 - 2⁵ = 991890463 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 62160 + ... + 76469.

It is an arithmetic number, because the mean of its divisors is an integer number (56145150).

Almost surely, 2^991890495 is an apocalyptic number.

991890495 is a deficient number, since it is larger than the sum of its proper divisors (804754305).

991890495 is a wasteful number, since it uses less digits than its factorization.

991890495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138696 (or 138690 counting only the distinct ones).

The product of its (nonzero) digits is 1049760, while the sum is 54.

The square root of 991890495 is about 31494.2930544567. The cubic root of 991890495 is about 997.2894914480.

The spelling of 991890495 in words is "nine hundred ninety-one million, eight hundred ninety thousand, four hundred ninety-five".