21399754 has 16 divisors (see below), whose sum is σ = 32606208. Its totient is φ = 10532592.

The previous prime is 21399751. The next prime is 21399761. The reversal of 21399754 is 45799312.

It is not an unprimeable number, because it can be changed into a prime (21399751) 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, 43699 + ... + 44185.

It is an arithmetic number, because the mean of its divisors is an integer number (2037888).

Almost surely, 2^21399754 is an apocalyptic number.

21399754 is a deficient number, since it is larger than the sum of its proper divisors (11206454).

21399754 is a wasteful number, since it uses less digits than its factorization.

21399754 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 789.

The product of its digits is 68040, while the sum is 40.

The square root of 21399754 is about 4625.9868136431. The cubic root of 21399754 is about 277.6320460227.

The spelling of 21399754 in words is "twenty-one million, three hundred ninety-nine thousand, seven hundred fifty-four".