19915980 has 48 divisors (see below), whose sum is σ = 63732480. Its totient is φ = 4552128.

The previous prime is 19915967. The next prime is 19915991. The reversal of 19915980 is 8951991.

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23290 + ... + 24129.

It is an arithmetic number, because the mean of its divisors is an integer number (1327760).

Almost surely, 2^19915980 is an apocalyptic number.

19915980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19915980 is an abundant number, since it is smaller than the sum of its proper divisors (43816500).

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

19915980 is a wasteful number, since it uses less digits than its factorization.

19915980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47438 (or 47436 counting only the distinct ones).

The product of its (nonzero) digits is 29160, while the sum is 42.

The square root of 19915980 is about 4462.7323468924. The cubic root of 19915980 is about 271.0611191876.

The spelling of 19915980 in words is "nineteen million, nine hundred fifteen thousand, nine hundred eighty".