21742368 has 24 divisors (see below), whose sum is σ = 57073968. Its totient is φ = 7247424.

The previous prime is 21742363. The next prime is 21742379. The reversal of 21742368 is 86324712.

It is a tau number, because it is divible by the number of its divisors (24).

It is not an unprimeable number, because it can be changed into a prime (21742363) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 113146 + ... + 113337.

It is an arithmetic number, because the mean of its divisors is an integer number (2378082).

Almost surely, 2^21742368 is an apocalyptic number.

It is an amenable number.

21742368 is an abundant number, since it is smaller than the sum of its proper divisors (35331600).

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

21742368 is a wasteful number, since it uses less digits than its factorization.

21742368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226496 (or 226488 counting only the distinct ones).

The product of its digits is 16128, while the sum is 33.

The square root of 21742368 is about 4662.8712184662. The cubic root of 21742368 is about 279.1058551833.

The spelling of 21742368 in words is "twenty-one million, seven hundred forty-two thousand, three hundred sixty-eight".