21957794 has 16 divisors (see below), whose sum is σ = 34136640. Its totient is φ = 10586160.

The previous prime is 21957781. The next prime is 21957799. The reversal of 21957794 is 49775912.

It is not an unprimeable number, because it can be changed into a prime (21957799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4499 + ... + 8009.

It is an arithmetic number, because the mean of its divisors is an integer number (2133540).

Almost surely, 2^21957794 is an apocalyptic number.

21957794 is a deficient number, since it is larger than the sum of its proper divisors (12178846).

21957794 is a wasteful number, since it uses less digits than its factorization.

21957794 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3625.

The product of its digits is 158760, while the sum is 44.

The square root of 21957794 is about 4685.9144251683. The cubic root of 21957794 is about 280.0246321867.

The spelling of 21957794 in words is "twenty-one million, nine hundred fifty-seven thousand, seven hundred ninety-four".