21964797 has 8 divisors (see below), whose sum is σ = 32540480. Its totient is φ = 14643180.

The previous prime is 21964763. The next prime is 21964801. The reversal of 21964797 is 79746912.

It is not a de Polignac number, because 21964797 - 2⁷ = 21964669 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 (21964727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 406729 + ... + 406782.

It is an arithmetic number, because the mean of its divisors is an integer number (4067560).

Almost surely, 2^21964797 is an apocalyptic number.

21964797 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

21964797 is a deficient number, since it is larger than the sum of its proper divisors (10575683).

21964797 is an equidigital number, since it uses as much as digits as its factorization.

21964797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 813520 (or 813514 counting only the distinct ones).

The product of its digits is 190512, while the sum is 45.

The square root of 21964797 is about 4686.6616050233. The cubic root of 21964797 is about 280.0543984444.

The spelling of 21964797 in words is "twenty-one million, nine hundred sixty-four thousand, seven hundred ninety-seven".