21742446 has 16 divisors (see below), whose sum is σ = 47438208. Its totient is φ = 6588600.

The previous prime is 21742411. The next prime is 21742447. The reversal of 21742446 is 64424712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21742447) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 164650 + ... + 164781.

It is an arithmetic number, because the mean of its divisors is an integer number (2964888).

Almost surely, 2^21742446 is an apocalyptic number.

21742446 is an abundant number, since it is smaller than the sum of its proper divisors (25695762).

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

21742446 is a wasteful number, since it uses less digits than its factorization.

21742446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329447.

The product of its digits is 10752, while the sum is 30.

The square root of 21742446 is about 4662.8795824040. The cubic root of 21742446 is about 279.1061889438.

It can be divided in two parts, 217424 and 46, that added together give a triangular number (217470 = T₆₅₉).

The spelling of 21742446 in words is "twenty-one million, seven hundred forty-two thousand, four hundred forty-six".