20977740 has 72 divisors (see below), whose sum is σ = 72727200. Its totient is φ = 4794624.

The previous prime is 20977709. The next prime is 20977753. The reversal of 20977740 is 4777902.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20977695 and 20977704.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7065 + ... + 9584.

It is an arithmetic number, because the mean of its divisors is an integer number (1010100).

Almost surely, 2^20977740 is an apocalyptic number.

20977740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20977740 is an abundant number, since it is smaller than the sum of its proper divisors (51749460).

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

20977740 is a wasteful number, since it uses less digits than its factorization.

20977740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16671 (or 16666 counting only the distinct ones).

The product of its (nonzero) digits is 24696, while the sum is 36.

The square root of 20977740 is about 4580.1462858734. The cubic root of 20977740 is about 275.7949011866.

The spelling of 20977740 in words is "twenty million, nine hundred seventy-seven thousand, seven hundred forty".