20977820 has 12 divisors (see below), whose sum is σ = 44053464. Its totient is φ = 8391120.

The previous prime is 20977819. The next prime is 20977841. The reversal of 20977820 is 2877902.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 524426 + ... + 524465.

It is an arithmetic number, because the mean of its divisors is an integer number (3671122).

Almost surely, 2^20977820 is an apocalyptic number.

20977820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20977820 is an abundant number, since it is smaller than the sum of its proper divisors (23075644).

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

20977820 is a wasteful number, since it uses less digits than its factorization.

20977820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1048900 (or 1048898 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 35.

The square root of 20977820 is about 4580.1550192106. The cubic root of 20977820 is about 275.7952517735.

The spelling of 20977820 in words is "twenty million, nine hundred seventy-seven thousand, eight hundred twenty".