20919216 has 20 divisors (see below), whose sum is σ = 54041432. Its totient is φ = 6973056.

The previous prime is 20919211. The next prime is 20919229. The reversal of 20919216 is 61291902.

It is a happy number.

It is a super-2 number, since 2×20919216² = 875227196109312, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20919211) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 217861 + ... + 217956.

Almost surely, 2^20919216 is an apocalyptic number.

It is an amenable number.

20919216 is an abundant number, since it is smaller than the sum of its proper divisors (33122216).

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

20919216 is a wasteful number, since it uses less digits than its factorization.

20919216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 435828 (or 435822 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 30.

The square root of 20919216 is about 4573.7529447927. The cubic root of 20919216 is about 275.5381901224.

The spelling of 20919216 in words is "twenty million, nine hundred nineteen thousand, two hundred sixteen".