21493194746 has 4 divisors (see below), whose sum is σ = 32239792122. Its totient is φ = 10746597372.

The previous prime is 21493194739. The next prime is 21493194769. The reversal of 21493194746 is 64749139412.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 18820821721 + 2672373025 = 137189^2 + 51695^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21493194694 and 21493194703.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5373298685 + ... + 5373298688.

Almost surely, 2^21493194746 is an apocalyptic number.

21493194746 is a deficient number, since it is larger than the sum of its proper divisors (10746597376).

21493194746 is a wasteful number, since it uses less digits than its factorization.

21493194746 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10746597375.

The product of its digits is 1306368, while the sum is 50.

The spelling of 21493194746 in words is "twenty-one billion, four hundred ninety-three million, one hundred ninety-four thousand, seven hundred forty-six".