19922991 has 16 divisors (see below), whose sum is σ = 30240000. Its totient is φ = 11549120.

The previous prime is 19922923. The next prime is 19922993.

19922991 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 19922991 - 2⁹ = 19922479 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19922993) 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, 12366 + ... + 13883.

It is an arithmetic number, because the mean of its divisors is an integer number (1890000).

Almost surely, 2^19922991 is an apocalyptic number.

19922991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

19922991 is a deficient number, since it is larger than the sum of its proper divisors (10317009).

19922991 is a wasteful number, since it uses less digits than its factorization.

19922991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26286.

The product of its digits is 26244, while the sum is 42.

The square root of 19922991 is about 4463.5177830944. The cubic root of 19922991 is about 271.0929225694.

The spelling of 19922991 in words is "nineteen million, nine hundred twenty-two thousand, nine hundred ninety-one".