21942153 has 6 divisors (see below), whose sum is σ = 31694234. Its totient is φ = 14628096.

The previous prime is 21942143. The next prime is 21942191. The reversal of 21942153 is 35124912.

It can be written as a sum of positive squares in only one way, i.e., 21930489 + 11664 = 4683^2 + 108^2 .

It is not a de Polignac number, because 21942153 - 2¹² = 21938057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21942113) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1219000 + ... + 1219017.

Almost surely, 2^21942153 is an apocalyptic number.

It is an amenable number.

21942153 is a deficient number, since it is larger than the sum of its proper divisors (9752081).

21942153 is a wasteful number, since it uses less digits than its factorization.

21942153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2438023 (or 2438020 counting only the distinct ones).

The product of its digits is 2160, while the sum is 27.

The square root of 21942153 is about 4684.2451899959. The cubic root of 21942153 is about 279.9581272418.

The spelling of 21942153 in words is "twenty-one million, nine hundred forty-two thousand, one hundred fifty-three".