19977944 has 16 divisors (see below), whose sum is σ = 42810000. Its totient is φ = 8561952.

The previous prime is 19977943. The next prime is 19977953. The reversal of 19977944 is 44977991.

It is a junction number, because it is equal to n+sod(n) for n = 19977892 and 19977901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19977943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 178319 + ... + 178430.

It is an arithmetic number, because the mean of its divisors is an integer number (2675625).

Almost surely, 2^19977944 is an apocalyptic number.

19977944 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

It is an amenable number.

19977944 is an abundant number, since it is smaller than the sum of its proper divisors (22832056).

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

19977944 is a wasteful number, since it uses less digits than its factorization.

19977944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356762 (or 356758 counting only the distinct ones).

The product of its digits is 571536, while the sum is 50.

The square root of 19977944 is about 4469.6693390004. The cubic root of 19977944 is about 271.3419429656.

The spelling of 19977944 in words is "nineteen million, nine hundred seventy-seven thousand, nine hundred forty-four".