21394893 has 24 divisors (see below), whose sum is σ = 32530080. Its totient is φ = 12467520.

The previous prime is 21394889. The next prime is 21394897. The reversal of 21394893 is 39849312.

It is an interprime number because it is at equal distance from previous prime (21394889) and next prime (21394897).

It is not a de Polignac number, because 21394893 - 2² = 21394889 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21394897) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8523 + ... + 10743.

It is an arithmetic number, because the mean of its divisors is an integer number (1355420).

Almost surely, 2^21394893 is an apocalyptic number.

It is an amenable number.

21394893 is a deficient number, since it is larger than the sum of its proper divisors (11135187).

21394893 is a wasteful number, since it uses less digits than its factorization.

21394893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2269 (or 2256 counting only the distinct ones).

The product of its digits is 46656, while the sum is 39.

The square root of 21394893 is about 4625.4613823920. The cubic root of 21394893 is about 277.6110228593.

The spelling of 21394893 in words is "twenty-one million, three hundred ninety-four thousand, eight hundred ninety-three".