19991064 has 32 divisors (see below), whose sum is σ = 50469120. Its totient is φ = 6598176.

The previous prime is 19991051. The next prime is 19991077. The reversal of 19991064 is 46019991.

It is an interprime number because it is at equal distance from previous prime (19991051) and next prime (19991077).

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, 1572 + ... + 6515.

It is an arithmetic number, because the mean of its divisors is an integer number (1577160).

Almost surely, 2^19991064 is an apocalyptic number.

It is an amenable number.

19991064 is an abundant number, since it is smaller than the sum of its proper divisors (30478056).

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

19991064 is a wasteful number, since it uses less digits than its factorization.

19991064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8199 (or 8195 counting only the distinct ones).

The product of its (nonzero) digits is 17496, while the sum is 39.

The square root of 19991064 is about 4471.1367682056. The cubic root of 19991064 is about 271.4013289107.

The spelling of 19991064 in words is "nineteen million, nine hundred ninety-one thousand, sixty-four".