21634319 has 16 divisors (see below), whose sum is σ = 27086400. Its totient is φ = 16848384.

The previous prime is 21634309. The next prime is 21634337. The reversal of 21634319 is 91343612.

It is not a de Polignac number, because 21634319 - 2¹² = 21630223 is a prime.

It is a super-2 number, since 2×21634319² = 936087517187522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21634291 and 21634300.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634309) 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, 317 + ... + 6585.

It is an arithmetic number, because the mean of its divisors is an integer number (1692900).

Almost surely, 2^21634319 is an apocalyptic number.

21634319 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

21634319 is a deficient number, since it is larger than the sum of its proper divisors (5452081).

21634319 is a wasteful number, since it uses less digits than its factorization.

21634319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6322.

The product of its digits is 3888, while the sum is 29.

The square root of 21634319 is about 4651.2706865974. The cubic root of 21634319 is about 278.6427470509.

The spelling of 21634319 in words is "twenty-one million, six hundred thirty-four thousand, three hundred nineteen".