21716394 has 32 divisors (see below), whose sum is σ = 50029056. Its totient is φ = 6155760.

The previous prime is 21716381. The next prime is 21716407. The reversal of 21716394 is 49361712.

It is an interprime number because it is at equal distance from previous prime (21716381) and next prime (21716407).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3529 + ... + 7475.

It is an arithmetic number, because the mean of its divisors is an integer number (1563408).

Almost surely, 2^21716394 is an apocalyptic number.

21716394 is an abundant number, since it is smaller than the sum of its proper divisors (28312662).

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

21716394 is a wasteful number, since it uses less digits than its factorization.

21716394 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4090.

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

The square root of 21716394 is about 4660.0851923543. The cubic root of 21716394 is about 278.9946685175.

The spelling of 21716394 in words is "twenty-one million, seven hundred sixteen thousand, three hundred ninety-four".