18381772426 has 16 divisors (see below), whose sum is σ = 27835564680. Its totient is φ = 9103311360.

The previous prime is 18381772411. The next prime is 18381772429. The reversal of 18381772426 is 62427718381.

It can be written as a sum of positive squares in 4 ways, for example, as 16270278025 + 2111494401 = 127555^2 + 45951^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18381772426.

It is not an unprimeable number, because it can be changed into a prime (18381772429) 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, 666870 + ... + 693886.

Almost surely, 2^18381772426 is an apocalyptic number.

18381772426 is a deficient number, since it is larger than the sum of its proper divisors (9453792254).

18381772426 is a wasteful number, since it uses less digits than its factorization.

18381772426 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30249.

The product of its digits is 903168, while the sum is 49.

The spelling of 18381772426 in words is "eighteen billion, three hundred eighty-one million, seven hundred seventy-two thousand, four hundred twenty-six".