19950912721 has 4 divisors (see below), whose sum is σ = 20203456000. Its totient is φ = 19698369444.

The previous prime is 19950912679. The next prime is 19950912731. The reversal of 19950912721 is 12721905991.

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 19950912721 - 2¹⁷ = 19950781649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19950912731) 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, 126271521 + ... + 126271678.

It is an arithmetic number, because the mean of its divisors is an integer number (5050864000).

Almost surely, 2^19950912721 is an apocalyptic number.

It is an amenable number.

19950912721 is a deficient number, since it is larger than the sum of its proper divisors (252543279).

19950912721 is an equidigital number, since it uses as much as digits as its factorization.

19950912721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252543278.

The product of its (nonzero) digits is 102060, while the sum is 46.

The spelling of 19950912721 in words is "nineteen billion, nine hundred fifty million, nine hundred twelve thousand, seven hundred twenty-one".