21024939 has 8 divisors (see below), whose sum is σ = 30189712. Its totient is φ = 12938400.

The previous prime is 21024911. The next prime is 21024953. The reversal of 21024939 is 93942012.

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

It is not a de Polignac number, because 21024939 - 2⁵ = 21024907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21024959) 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, 269512 + ... + 269589.

It is an arithmetic number, because the mean of its divisors is an integer number (3773714).

Almost surely, 2^21024939 is an apocalyptic number.

21024939 is a deficient number, since it is larger than the sum of its proper divisors (9164773).

21024939 is a wasteful number, since it uses less digits than its factorization.

21024939 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 539117.

The product of its (nonzero) digits is 3888, while the sum is 30.

The square root of 21024939 is about 4585.2959555518. The cubic root of 21024939 is about 276.0015884177.

The spelling of 21024939 in words is "twenty-one million, twenty-four thousand, nine hundred thirty-nine".