19400988 has 12 divisors (see below), whose sum is σ = 45269000. Its totient is φ = 6466992.

The previous prime is 19400959. The next prime is 19400999. The reversal of 19400988 is 88900491.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×19400988² = 752796670752288, which contains 22 as substring.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 808363 + ... + 808386.

Almost surely, 2^19400988 is an apocalyptic number.

It is an amenable number.

19400988 is an abundant number, since it is smaller than the sum of its proper divisors (25868012).

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

19400988 is a wasteful number, since it uses less digits than its factorization.

19400988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1616756 (or 1616754 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 19400988 is about 4404.6552646036. The cubic root of 19400988 is about 268.7042995665.

The spelling of 19400988 in words is "nineteen million, four hundred thousand, nine hundred eighty-eight".