21736642 has 32 divisors (see below), whose sum is σ = 36578304. Its totient is φ = 9638400.

The previous prime is 21736619. The next prime is 21736657. The reversal of 21736642 is 24663712.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42963 + ... + 43465.

It is an arithmetic number, because the mean of its divisors is an integer number (1143072).

Almost surely, 2^21736642 is an apocalyptic number.

21736642 is a deficient number, since it is larger than the sum of its proper divisors (14841662).

21736642 is a wasteful number, since it uses less digits than its factorization.

21736642 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 594.

The product of its digits is 12096, while the sum is 31.

The square root of 21736642 is about 4662.2571786636. The cubic root of 21736642 is about 279.0813515591.

The spelling of 21736642 in words is "twenty-one million, seven hundred thirty-six thousand, six hundred forty-two".