21426394 has 32 divisors (see below), whose sum is σ = 36702720. Its totient is φ = 9292800.

The previous prime is 21426371. The next prime is 21426401. The reversal of 21426394 is 49362412.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 60522 + ... + 60874.

It is an arithmetic number, because the mean of its divisors is an integer number (1146960).

Almost surely, 2^21426394 is an apocalyptic number.

21426394 is a deficient number, since it is larger than the sum of its proper divisors (15276326).

21426394 is a wasteful number, since it uses less digits than its factorization.

21426394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486.

The product of its digits is 10368, while the sum is 31.

The square root of 21426394 is about 4628.8653037219. The cubic root of 21426394 is about 277.7472039002.

The spelling of 21426394 in words is "twenty-one million, four hundred twenty-six thousand, three hundred ninety-four".