21493716 has 24 divisors (see below), whose sum is σ = 50975904. Its totient is φ = 7046880.

The previous prime is 21493699. The next prime is 21493723. The reversal of 21493716 is 61739412.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13950 + ... + 15413.

It is an arithmetic number, because the mean of its divisors is an integer number (2123996).

Almost surely, 2^21493716 is an apocalyptic number.

It is an amenable number.

21493716 is an abundant number, since it is smaller than the sum of its proper divisors (29482188).

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

21493716 is a wasteful number, since it uses less digits than its factorization.

21493716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29431 (or 29429 counting only the distinct ones).

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

The square root of 21493716 is about 4636.1315770802. The cubic root of 21493716 is about 278.0377948373.

The spelling of 21493716 in words is "twenty-one million, four hundred ninety-three thousand, seven hundred sixteen".