21293748 has 36 divisors (see below), whose sum is σ = 61516000. Its totient is φ = 6083856.

The previous prime is 21293747. The next prime is 21293761. The reversal of 21293748 is 84739212.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21293747) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 41998 + ... + 42501.

Almost surely, 2^21293748 is an apocalyptic number.

21293748 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21293748 is an abundant number, since it is smaller than the sum of its proper divisors (40222252).

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

21293748 is a wasteful number, since it uses less digits than its factorization.

21293748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84516 (or 84511 counting only the distinct ones).

The product of its digits is 24192, while the sum is 36.

The square root of 21293748 is about 4614.5149257533. The cubic root of 21293748 is about 277.1728601703.

The spelling of 21293748 in words is "twenty-one million, two hundred ninety-three thousand, seven hundred forty-eight".