21716290 has 16 divisors (see below), whose sum is σ = 39999168. Its totient is φ = 8484336.

The previous prime is 21716287. The next prime is 21716291. The reversal of 21716290 is 9261712.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21716291) 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, 24822 + ... + 25681.

It is an arithmetic number, because the mean of its divisors is an integer number (2499948).

Almost surely, 2^21716290 is an apocalyptic number.

21716290 is a deficient number, since it is larger than the sum of its proper divisors (18282878).

21716290 is a wasteful number, since it uses less digits than its factorization.

21716290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50553.

The product of its (nonzero) digits is 1512, while the sum is 28.

The square root of 21716290 is about 4660.0740337467. The cubic root of 21716290 is about 278.9942231475.

The spelling of 21716290 in words is "twenty-one million, seven hundred sixteen thousand, two hundred ninety".