19910974042 has 16 divisors (see below), whose sum is σ = 29928429864. Its totient is φ = 9934848000.

The previous prime is 19910974003. The next prime is 19910974043. The reversal of 19910974042 is 24047901991.

It can be written as a sum of positive squares in 4 ways, for example, as 19742779081 + 168194961 = 140509^2 + 12969^2 .

It is a junction number, because it is equal to n+sod(n) for n = 19910973983 and 19910974001.

It is not an unprimeable number, because it can be changed into a prime (19910974043) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4306492 + ... + 4311112.

Almost surely, 2^19910974042 is an apocalyptic number.

19910974042 is a deficient number, since it is larger than the sum of its proper divisors (10017455822).

19910974042 is a wasteful number, since it uses less digits than its factorization.

19910974042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8625.

The product of its (nonzero) digits is 163296, while the sum is 46.

The spelling of 19910974042 in words is "nineteen billion, nine hundred ten million, nine hundred seventy-four thousand, forty-two".