18981975402 has 64 divisors (see below), whose sum is σ = 45510917760. Its totient is φ = 5829812352.

The previous prime is 18981975401. The next prime is 18981975409. The reversal of 18981975402 is 20457918981.

It is a happy number.

18981975402 is a `hidden beast` number, since 1 + 8 + 9 + 8 + 1 + 97 + 540 + 2 = 666.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (18981975401) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 359278 + ... + 408710.

It is an arithmetic number, because the mean of its divisors is an integer number (711108090).

Almost surely, 2^18981975402 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18981975402, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22755458880).

18981975402 is an abundant number, since it is smaller than the sum of its proper divisors (26528942358).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18981975402 is a wasteful number, since it uses less digits than its factorization.

18981975402 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50004 (or 49998 counting only the distinct ones).

The product of its (nonzero) digits is 1451520, while the sum is 54.

The spelling of 18981975402 in words is "eighteen billion, nine hundred eighty-one million, nine hundred seventy-five thousand, four hundred two".