921623989 has 16 divisors (see below), whose sum is σ = 1087640064. Its totient is φ = 769896000.

The previous prime is 921623981. The next prime is 921623999. The reversal of 921623989 is 989326129.

It is a cyclic number.

It is not a de Polignac number, because 921623989 - 2³ = 921623981 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 (921623981) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17439 + ... + 46339.

It is an arithmetic number, because the mean of its divisors is an integer number (67977504).

Almost surely, 2^921623989 is an apocalyptic number.

It is an amenable number.

921623989 is a deficient number, since it is larger than the sum of its proper divisors (166016075).

921623989 is a wasteful number, since it uses less digits than its factorization.

921623989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29148.

The product of its digits is 419904, while the sum is 49.

The square root of 921623989 is about 30358.2606385807. The cubic root of 921623989 is about 973.1607628495.

The spelling of 921623989 in words is "nine hundred twenty-one million, six hundred twenty-three thousand, nine hundred eighty-nine".