21745342 has 4 divisors (see below), whose sum is σ = 32618016. Its totient is φ = 10872670.

The previous prime is 21745337. The next prime is 21745357. The reversal of 21745342 is 24354712.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21745342.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5436334 + ... + 5436337.

It is an arithmetic number, because the mean of its divisors is an integer number (8154504).

Almost surely, 2^21745342 is an apocalyptic number.

21745342 is a deficient number, since it is larger than the sum of its proper divisors (10872674).

21745342 is a wasteful number, since it uses less digits than its factorization.

21745342 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10872673.

The product of its digits is 6720, while the sum is 28.

The square root of 21745342 is about 4663.1901097854. The cubic root of 21745342 is about 279.1185803070.

The spelling of 21745342 in words is "twenty-one million, seven hundred forty-five thousand, three hundred forty-two".