19900378505 has 32 divisors (see below), whose sum is σ = 27411072000. Its totient is φ = 13586553792.

The previous prime is 19900378499. The next prime is 19900378507. The reversal of 19900378505 is 50587300991.

It is not a de Polignac number, because 19900378505 - 2³⁴ = 2720509321 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19900378505.

It is not an unprimeable number, because it can be changed into a prime (19900378507) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 11712146 + ... + 11713844.

It is an arithmetic number, because the mean of its divisors is an integer number (856596000).

Almost surely, 2^19900378505 is an apocalyptic number.

It is an amenable number.

19900378505 is a deficient number, since it is larger than the sum of its proper divisors (7510693495).

19900378505 is a wasteful number, since it uses less digits than its factorization.

19900378505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2973.

The product of its (nonzero) digits is 340200, while the sum is 47.

The spelling of 19900378505 in words is "nineteen billion, nine hundred million, three hundred seventy-eight thousand, five hundred five".