19930725681 has 4 divisors (see below), whose sum is σ = 26574300912. Its totient is φ = 13287150452.

The previous prime is 19930725677. The next prime is 19930725691. The reversal of 19930725681 is 18652703991.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 19930725681 - 2² = 19930725677 is a prime.

It is a super-2 number, since 2×19930725681² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (19930725691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3321787611 + ... + 3321787616.

It is an arithmetic number, because the mean of its divisors is an integer number (6643575228).

Almost surely, 2^19930725681 is an apocalyptic number.

It is an amenable number.

19930725681 is a deficient number, since it is larger than the sum of its proper divisors (6643575231).

19930725681 is an equidigital number, since it uses as much as digits as its factorization.

19930725681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6643575230.

The product of its (nonzero) digits is 816480, while the sum is 51.

The spelling of 19930725681 in words is "nineteen billion, nine hundred thirty million, seven hundred twenty-five thousand, six hundred eighty-one".