18261564650 has 96 divisors (see below), whose sum is σ = 39806976000. Its totient is φ = 6102371520.

The previous prime is 18261564649. The next prime is 18261564653. The reversal of 18261564650 is 5646516281.

It is a super-2 number, since 2×18261564650² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (18261564653) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9134351 + ... + 9136349.

It is an arithmetic number, because the mean of its divisors is an integer number (414656000).

Almost surely, 2^18261564650 is an apocalyptic number.

18261564650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18261564650 is an abundant number, since it is smaller than the sum of its proper divisors (21545411350).

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

18261564650 is a wasteful number, since it uses less digits than its factorization.

18261564650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2668 (or 2663 counting only the distinct ones).

The product of its (nonzero) digits is 345600, while the sum is 44.

The spelling of 18261564650 in words is "eighteen billion, two hundred sixty-one million, five hundred sixty-four thousand, six hundred fifty".