19905399754 has 4 divisors (see below), whose sum is σ = 29858099634. Its totient is φ = 9952699876.

The previous prime is 19905399733. The next prime is 19905399781. The reversal of 19905399754 is 45799350991.

19905399754 is digitally balanced in base 5, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 45799350991 = 571 ⋅80209021.

It can be written as a sum of positive squares in only one way, i.e., 16198416529 + 3706983225 = 127273^2 + 60885^2 .

It is a junction number, because it is equal to n+sod(n) for n = 19905399692 and 19905399701.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4976349937 + ... + 4976349940.

Almost surely, 2^19905399754 is an apocalyptic number.

19905399754 is a deficient number, since it is larger than the sum of its proper divisors (9952699880).

19905399754 is an equidigital number, since it uses as much as digits as its factorization.

19905399754 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9952699879.

The product of its (nonzero) digits is 13778100, while the sum is 61.

The spelling of 19905399754 in words is "nineteen billion, nine hundred five million, three hundred ninety-nine thousand, seven hundred fifty-four".