21379263 has 8 divisors (see below), whose sum is σ = 28533888. Its totient is φ = 14238744.

The previous prime is 21379249. The next prime is 21379271. The reversal of 21379263 is 36297312.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21379263 - 2⁹ = 21378751 is a prime.

It is a super-3 number, since 3×21379263³ (a number of 23 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21379283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 756 + ... + 6582.

It is an arithmetic number, because the mean of its divisors is an integer number (3566736).

Almost surely, 2^21379263 is an apocalyptic number.

21379263 is a deficient number, since it is larger than the sum of its proper divisors (7154625).

21379263 is a wasteful number, since it uses less digits than its factorization.

21379263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7053.

The product of its digits is 13608, while the sum is 33.

The square root of 21379263 is about 4623.7715125209. The cubic root of 21379263 is about 277.5434036484.

The spelling of 21379263 in words is "twenty-one million, three hundred seventy-nine thousand, two hundred sixty-three".