1978820020 has 24 divisors (see below), whose sum is σ = 4188248064. Its totient is φ = 785294496.

The previous prime is 1978819987. The next prime is 1978820021. The reversal of 1978820020 is 200288791.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1978820021) 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, 386992 + ... + 392071.

It is an arithmetic number, because the mean of its divisors is an integer number (174510336).

Almost surely, 2^1978820020 is an apocalyptic number.

1978820020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1978820020 is an abundant number, since it is smaller than the sum of its proper divisors (2209428044).

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

1978820020 is a wasteful number, since it uses less digits than its factorization.

1978820020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779199 (or 779197 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 37.

The square root of 1978820020 is about 44483.9299073272. The cubic root of 1978820020 is about 1255.4577400441.

The spelling of 1978820020 in words is "one billion, nine hundred seventy-eight million, eight hundred twenty thousand, twenty".