19045151981 has 4 divisors (see below), whose sum is σ = 19241493852. Its totient is φ = 18848810112.

The previous prime is 19045151977. The next prime is 19045152011. The reversal of 19045151981 is 18915154091.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7768835881 + 11276316100 = 88141^2 + 106190^2 .

It is a cyclic number.

It is not a de Polignac number, because 19045151981 - 2² = 19045151977 is a prime.

It is a super-2 number, since 2×19045151981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19045151911) 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, 98170790 + ... + 98170983.

It is an arithmetic number, because the mean of its divisors is an integer number (4810373463).

Almost surely, 2^19045151981 is an apocalyptic number.

It is an amenable number.

19045151981 is a deficient number, since it is larger than the sum of its proper divisors (196341871).

19045151981 is an equidigital number, since it uses as much as digits as its factorization.

19045151981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196341870.

The product of its (nonzero) digits is 64800, while the sum is 44.

The spelling of 19045151981 in words is "nineteen billion, forty-five million, one hundred fifty-one thousand, nine hundred eighty-one".