19695034921 has 3 divisors (see below), whose sum is σ = 19695175261. Its totient is φ = 19694894582.

The previous prime is 19695034913. The next prime is 19695034937. The reversal of 19695034921 is 12943059691.

The square root of 19695034921 is 140339.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 19695034921 - 2³ = 19695034913 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19695034901) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 70170 + ... + 210508.

Almost surely, 2^19695034921 is an apocalyptic number.

19695034921 is the 140339-th square number.

19695034921 is the 70170-th centered octagonal number.

It is an amenable number.

19695034921 is a deficient number, since it is larger than the sum of its proper divisors (140340).

19695034921 is an frugal number, since it uses more digits than its factorization.

19695034921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280678 (or 140339 counting only the distinct ones).

The product of its (nonzero) digits is 524880, while the sum is 49.

Multiplying 19695034921 by its sum of digits (49), we get a square (965056711129 = 982373²).

The spelling of 19695034921 in words is "nineteen billion, six hundred ninety-five million, thirty-four thousand, nine hundred twenty-one".