20977240 has 32 divisors (see below), whose sum is σ = 48353760. Its totient is φ = 8185600.

The previous prime is 20977217. The next prime is 20977247. The reversal of 20977240 is 4277902.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20977247) 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, 4756 + ... + 8035.

It is an arithmetic number, because the mean of its divisors is an integer number (1511055).

Almost surely, 2^20977240 is an apocalyptic number.

20977240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20977240 is an abundant number, since it is smaller than the sum of its proper divisors (27376520).

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

20977240 is a wasteful number, since it uses less digits than its factorization.

20977240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12843 (or 12839 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 20977240 is about 4580.0917021387. The cubic root of 20977240 is about 275.7927099981.

The spelling of 20977240 in words is "twenty million, nine hundred seventy-seven thousand, two hundred forty".