21942357 has 16 divisors (see below), whose sum is σ = 30456000. Its totient is φ = 14034944.

The previous prime is 21942317. The next prime is 21942377. The reversal of 21942357 is 75324912.

It is a cyclic number.

It is not a de Polignac number, because 21942357 - 2¹¹ = 21940309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21942317) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14869 + ... + 16277.

It is an arithmetic number, because the mean of its divisors is an integer number (1903500).

Almost surely, 2^21942357 is an apocalyptic number.

It is an amenable number.

21942357 is a deficient number, since it is larger than the sum of its proper divisors (8513643).

21942357 is a wasteful number, since it uses less digits than its factorization.

21942357 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1620.

The product of its digits is 15120, while the sum is 33.

The square root of 21942357 is about 4684.2669650651. The cubic root of 21942357 is about 279.9589948456.

The spelling of 21942357 in words is "twenty-one million, nine hundred forty-two thousand, three hundred fifty-seven".