21506694 has 32 divisors (see below), whose sum is σ = 48197376. Its totient is φ = 6340320.

The previous prime is 21506669. The next prime is 21506707. The reversal of 21506694 is 49660512.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1962 + ... + 6845.

It is an arithmetic number, because the mean of its divisors is an integer number (1506168).

Almost surely, 2^21506694 is an apocalyptic number.

21506694 is an abundant number, since it is smaller than the sum of its proper divisors (26690682).

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

21506694 is a wasteful number, since it uses less digits than its factorization.

21506694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8860.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 21506694 is about 4637.5310241550. The cubic root of 21506694 is about 278.0937437248.

The spelling of 21506694 in words is "twenty-one million, five hundred six thousand, six hundred ninety-four".