21739416 has 32 divisors (see below), whose sum is σ = 56712960. Its totient is φ = 6931232.

The previous prime is 21739411. The next prime is 21739433. The reversal of 21739416 is 61493712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21739411) 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, 19140 + ... + 20243.

It is an arithmetic number, because the mean of its divisors is an integer number (1772280).

Almost surely, 2^21739416 is an apocalyptic number.

It is an amenable number.

21739416 is an abundant number, since it is smaller than the sum of its proper divisors (34973544).

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

21739416 is a wasteful number, since it uses less digits than its factorization.

21739416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39415 (or 39411 counting only the distinct ones).

The product of its digits is 9072, while the sum is 33.

The square root of 21739416 is about 4662.5546645589. The cubic root of 21739416 is about 279.0932230453.

It can be divided in two parts, 21739 and 416, that added together give a triangular number (22155 = T₂₁₀).

The spelling of 21739416 in words is "twenty-one million, seven hundred thirty-nine thousand, four hundred sixteen".