21977016 has 64 divisors (see below), whose sum is σ = 57446400. Its totient is φ = 6998400.

The previous prime is 21976979. The next prime is 21977023. The reversal of 21977016 is 61077912.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a congruent number.

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, 80961 + ... + 81231.

It is an arithmetic number, because the mean of its divisors is an integer number (897600).

Almost surely, 2^21977016 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21977016, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28723200).

21977016 is an abundant number, since it is smaller than the sum of its proper divisors (35469384).

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

21977016 is a wasteful number, since it uses less digits than its factorization.

21977016 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420 (or 416 counting only the distinct ones).

The product of its (nonzero) digits is 5292, while the sum is 33.

The square root of 21977016 is about 4687.9650169343. The cubic root of 21977016 is about 280.1063201678.

The spelling of 21977016 in words is "twenty-one million, nine hundred seventy-seven thousand, sixteen".