21263190 has 32 divisors (see below), whose sum is σ = 54958176. Its totient is φ = 5233920.

The previous prime is 21263183. The next prime is 21263191. The reversal of 21263190 is 9136212.

It is a super-2 number, since 2×21263190² = 904246497952200, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21263190.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21263191) 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, 26871 + ... + 27650.

It is an arithmetic number, because the mean of its divisors is an integer number (1717443).

Almost surely, 2^21263190 is an apocalyptic number.

21263190 is an abundant number, since it is smaller than the sum of its proper divisors (33694986).

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

21263190 is a wasteful number, since it uses less digits than its factorization.

21263190 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54544.

The product of its (nonzero) digits is 648, while the sum is 24.

The square root of 21263190 is about 4611.2026630804. The cubic root of 21263190 is about 277.0402092924.

The spelling of 21263190 in words is "twenty-one million, two hundred sixty-three thousand, one hundred ninety".