21654929 has 16 divisors (see below), whose sum is σ = 23151744. Its totient is φ = 20227200.

The previous prime is 21654907. The next prime is 21654931. The reversal of 21654929 is 92945612.

It is a de Polignac number, because none of the positive numbers 2^k-21654929 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21654892 and 21654901.

It is not an unprimeable number, because it can be changed into a prime (21654989) 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, 125087 + ... + 125259.

It is an arithmetic number, because the mean of its divisors is an integer number (1446984).

Almost surely, 2^21654929 is an apocalyptic number.

It is an amenable number.

21654929 is a deficient number, since it is larger than the sum of its proper divisors (1496815).

21654929 is a wasteful number, since it uses less digits than its factorization.

21654929 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328.

The product of its digits is 38880, while the sum is 38.

The square root of 21654929 is about 4653.4856827974. The cubic root of 21654929 is about 278.7312022555.

The spelling of 21654929 in words is "twenty-one million, six hundred fifty-four thousand, nine hundred twenty-nine".