21077982 has 40 divisors (see below), whose sum is σ = 49292496. Its totient is φ = 6719328.

The previous prime is 21077971. The next prime is 21078053. The reversal of 21077982 is 28977012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 898 + ... + 6554.

Almost surely, 2^21077982 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21077982, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24646248).

21077982 is an abundant number, since it is smaller than the sum of its proper divisors (28214514).

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

21077982 is a wasteful number, since it uses less digits than its factorization.

21077982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5694 (or 5685 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 21077982 is about 4591.0763443881. The cubic root of 21077982 is about 276.2334980554.

The spelling of 21077982 in words is "twenty-one million, seventy-seven thousand, nine hundred eighty-two".