921690671 has 4 divisors (see below), whose sum is σ = 1005480744. Its totient is φ = 837900600.

The previous prime is 921690613. The next prime is 921690677. The reversal of 921690671 is 176096129.

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

It is a cyclic number.

It is not a de Polignac number, because 921690671 - 2¹⁸ = 921428527 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 (921690677) 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, 41895020 + ... + 41895041.

It is an arithmetic number, because the mean of its divisors is an integer number (251370186).

Almost surely, 2^921690671 is an apocalyptic number.

921690671 is a deficient number, since it is larger than the sum of its proper divisors (83790073).

921690671 is a wasteful number, since it uses less digits than its factorization.

921690671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83790072.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 921690671 is about 30359.3588700420. The cubic root of 921690671 is about 973.1842325587.

The spelling of 921690671 in words is "nine hundred twenty-one million, six hundred ninety thousand, six hundred seventy-one".