19771493901 has 32 divisors (see below), whose sum is σ = 28629739008. Its totient is φ = 12089241600.

The previous prime is 19771493897. The next prime is 19771493909. The reversal of 19771493901 is 10939417791.

It is not a de Polignac number, because 19771493901 - 2² = 19771493897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19771493909) 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, 540801 + ... + 576201.

It is an arithmetic number, because the mean of its divisors is an integer number (894679344).

Almost surely, 2^19771493901 is an apocalyptic number.

It is an amenable number.

19771493901 is a deficient number, since it is larger than the sum of its proper divisors (8858245107).

19771493901 is a wasteful number, since it uses less digits than its factorization.

19771493901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35701.

The product of its (nonzero) digits is 428652, while the sum is 51.

The spelling of 19771493901 in words is "nineteen billion, seven hundred seventy-one million, four hundred ninety-three thousand, nine hundred one".