18205525840 has 80 divisors (see below), whose sum is σ = 42645449088. Its totient is φ = 7227790848.

The previous prime is 18205525817. The next prime is 18205525861. The reversal of 18205525840 is 4852550281.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×18205525840² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 18205525793 and 18205525802.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6269829 + ... + 6272731.

Almost surely, 2^18205525840 is an apocalyptic number.

18205525840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18205525840 is an abundant number, since it is smaller than the sum of its proper divisors (24439923248).

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

18205525840 is a wasteful number, since it uses less digits than its factorization.

18205525840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3476 (or 3470 counting only the distinct ones).

The product of its (nonzero) digits is 128000, while the sum is 40.

The spelling of 18205525840 in words is "eighteen billion, two hundred five million, five hundred twenty-five thousand, eight hundred forty".