21243159 has 24 divisors (see below), whose sum is σ = 36915840. Its totient is φ = 11499408.

The previous prime is 21243151. The next prime is 21243181. The reversal of 21243159 is 95134212.

It is not a de Polignac number, because 21243159 - 2³ = 21243151 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21243151) 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, 7677 + ... + 10070.

It is an arithmetic number, because the mean of its divisors is an integer number (1538160).

Almost surely, 2^21243159 is an apocalyptic number.

21243159 is a deficient number, since it is larger than the sum of its proper divisors (15672681).

21243159 is a wasteful number, since it uses less digits than its factorization.

21243159 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17779 (or 17776 counting only the distinct ones).

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

The square root of 21243159 is about 4609.0301582871. The cubic root of 21243159 is about 276.9531866655.

The spelling of 21243159 in words is "twenty-one million, two hundred forty-three thousand, one hundred fifty-nine".