21263946 has 32 divisors (see below), whose sum is σ = 46656000. Its totient is φ = 6407280.

The previous prime is 21263941. The next prime is 21263959. The reversal of 21263946 is 64936212.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21263941) 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 15 ways as a sum of consecutive naturals, for example, 12325 + ... + 13943.

It is an arithmetic number, because the mean of its divisors is an integer number (1458000).

Almost surely, 2^21263946 is an apocalyptic number.

21263946 is an abundant number, since it is smaller than the sum of its proper divisors (25392054).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21263946 is a wasteful number, since it uses less digits than its factorization.

21263946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1834.

The product of its digits is 15552, while the sum is 33.

The square root of 21263946 is about 4611.2846366278. The cubic root of 21263946 is about 277.0434925864.

The spelling of 21263946 in words is "twenty-one million, two hundred sixty-three thousand, nine hundred forty-six".