18540531690 has 64 divisors (see below), whose sum is σ = 45649723392. Its totient is φ = 4816448000.

The previous prime is 18540531673. The next prime is 18540531697. The reversal of 18540531690 is 9613504581.

It is a super-2 number, since 2×18540531690² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18540531697) 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, 851479 + ... + 872981.

It is an arithmetic number, because the mean of its divisors is an integer number (713276928).

Almost surely, 2^18540531690 is an apocalyptic number.

18540531690 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 18540531690, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22824861696).

18540531690 is an abundant number, since it is smaller than the sum of its proper divisors (27109191702).

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

18540531690 is a wasteful number, since it uses less digits than its factorization.

18540531690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22255.

The product of its (nonzero) digits is 129600, while the sum is 42.

The spelling of 18540531690 in words is "eighteen billion, five hundred forty million, five hundred thirty-one thousand, six hundred ninety".