921052991 has 4 divisors (see below), whose sum is σ = 942472872. Its totient is φ = 899633112.

The previous prime is 921052981. The next prime is 921052999. The reversal of 921052991 is 199250129.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 199250129 = 13 ⋅15326933.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-921052991 is a prime.

It is a super-2 number, since 2×921052991² = 1696677224460092162, 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 (921052999) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10709876 + ... + 10709961.

It is an arithmetic number, because the mean of its divisors is an integer number (235618218).

Almost surely, 2^921052991 is an apocalyptic number.

921052991 is a deficient number, since it is larger than the sum of its proper divisors (21419881).

921052991 is a wasteful number, since it uses less digits than its factorization.

921052991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21419880.

The product of its (nonzero) digits is 14580, while the sum is 38.

The square root of 921052991 is about 30348.8548548376. The cubic root of 921052991 is about 972.9597453513.

The spelling of 921052991 in words is "nine hundred twenty-one million, fifty-two thousand, nine hundred ninety-one".