21741742 has 32 divisors (see below), whose sum is σ = 38327904. Its totient is φ = 9139200.

The previous prime is 21741689. The next prime is 21741743. The reversal of 21741742 is 24714712.

It is a self number, because there is not a number n which added to its sum of digits gives 21741742.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21741743) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22338 + ... + 23290.

It is an arithmetic number, because the mean of its divisors is an integer number (1197747).

Almost surely, 2^21741742 is an apocalyptic number.

21741742 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21741742 is a deficient number, since it is larger than the sum of its proper divisors (16586162).

21741742 is a wasteful number, since it uses less digits than its factorization.

21741742 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1044.

The product of its digits is 3136, while the sum is 28.

The square root of 21741742 is about 4662.8040919601. The cubic root of 21741742 is about 279.1031765124.

It can be divided in two parts, 2174 and 1742, that added together give a triangular number (3916 = T₈₈).

The spelling of 21741742 in words is "twenty-one million, seven hundred forty-one thousand, seven hundred forty-two".