19999740 has 48 divisors (see below), whose sum is σ = 56260512. Its totient is φ = 5308416.

The previous prime is 19999739. The next prime is 19999789. The reversal of 19999740 is 4799991.

It is a self number, because there is not a number n which added to its sum of digits gives 19999740.

It is a congruent number.

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, 14772 + ... + 16068.

It is an arithmetic number, because the mean of its divisors is an integer number (1172094).

Almost surely, 2^19999740 is an apocalyptic number.

19999740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19999740 is an abundant number, since it is smaller than the sum of its proper divisors (36260772).

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

19999740 is a wasteful number, since it uses less digits than its factorization.

19999740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1566 (or 1564 counting only the distinct ones).

The product of its (nonzero) digits is 183708, while the sum is 48.

The square root of 19999740 is about 4472.1068860214. The cubic root of 19999740 is about 271.4405854068.

The spelling of 19999740 in words is "nineteen million, nine hundred ninety-nine thousand, seven hundred forty".