21024738 has 32 divisors (see below), whose sum is σ = 53397120. Its totient is φ = 6006960.

The previous prime is 21024643. The next prime is 21024743. The reversal of 21024738 is 83742012.

It is a Harshad number since it is a multiple of its sum of digits (27).

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, 27433 + ... + 28188.

It is an arithmetic number, because the mean of its divisors is an integer number (1668660).

Almost surely, 2^21024738 is an apocalyptic number.

21024738 is an abundant number, since it is smaller than the sum of its proper divisors (32372382).

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

21024738 is a wasteful number, since it uses less digits than its factorization.

21024738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55639 (or 55633 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21024738 is about 4585.2740376121. The cubic root of 21024738 is about 276.0007088829. Note that the first 3 decimals are identical.

The spelling of 21024738 in words is "twenty-one million, twenty-four thousand, seven hundred thirty-eight".