19870940 has 24 divisors (see below), whose sum is σ = 41830992. Its totient is φ = 7928960.

The previous prime is 19870931. The next prime is 19870951. The reversal of 19870940 is 4907891.

It is a junction number, because it is equal to n+sod(n) for n = 19870894 and 19870903.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9467 + ... + 11373.

It is an arithmetic number, because the mean of its divisors is an integer number (1742958).

Almost surely, 2^19870940 is an apocalyptic number.

19870940 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19870940 is an abundant number, since it is smaller than the sum of its proper divisors (21960052).

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

19870940 is a wasteful number, since it uses less digits than its factorization.

19870940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2437 (or 2435 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 38.

The square root of 19870940 is about 4457.6832547861. The cubic root of 19870940 is about 270.8566300013.

The spelling of 19870940 in words is "nineteen million, eight hundred seventy thousand, nine hundred forty".