20322991 has 8 divisors (see below), whose sum is σ = 22047984. Its totient is φ = 18621120.

The previous prime is 20322983. The next prime is 20323013. The reversal of 20322991 is 19922302.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20322991 - 2³ = 20322983 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 (20322971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3925 + ... + 7486.

It is an arithmetic number, because the mean of its divisors is an integer number (2755998).

Almost surely, 2^20322991 is an apocalyptic number.

20322991 is a deficient number, since it is larger than the sum of its proper divisors (1724993).

20322991 is a wasteful number, since it uses less digits than its factorization.

20322991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11561.

The product of its (nonzero) digits is 1944, while the sum is 28.

The square root of 20322991 is about 4508.1028160414. The cubic root of 20322991 is about 272.8951862303.

Subtracting from 20322991 its reverse (19922302), we obtain a square (400689 = 633²).

The spelling of 20322991 in words is "twenty million, three hundred twenty-two thousand, nine hundred ninety-one".