21693942 has 12 divisors (see below), whose sum is σ = 47003580. Its totient is φ = 7231308.

The previous prime is 21693937. The next prime is 21693949. The reversal of 21693942 is 24939612.

It is a junction number, because it is equal to n+sod(n) for n = 21693897 and 21693906.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21693949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 602592 + ... + 602627.

It is an arithmetic number, because the mean of its divisors is an integer number (3916965).

Almost surely, 2^21693942 is an apocalyptic number.

21693942 is an abundant number, since it is smaller than the sum of its proper divisors (25309638).

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

21693942 is a wasteful number, since it uses less digits than its factorization.

21693942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1205227 (or 1205224 counting only the distinct ones).

The product of its digits is 23328, while the sum is 36.

The square root of 21693942 is about 4657.6756005544. The cubic root of 21693942 is about 278.8984869835.

The spelling of 21693942 in words is "twenty-one million, six hundred ninety-three thousand, nine hundred forty-two".