21780258180 has 96 divisors (see below), whose sum is σ = 61483847040. Its totient is φ = 5760706560.

The previous prime is 21780258127. The next prime is 21780258191. The reversal of 21780258180 is 8185208712.

It is a super-3 number, since 3×21780258180³ (a number of 32 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4519132 + ... + 4523948.

It is an arithmetic number, because the mean of its divisors is an integer number (640456740).

Almost surely, 2^21780258180 is an apocalyptic number.

21780258180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21780258180 is an abundant number, since it is smaller than the sum of its proper divisors (39703588860).

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

21780258180 is a wasteful number, since it uses less digits than its factorization.

21780258180 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5429 (or 5427 counting only the distinct ones).

The product of its (nonzero) digits is 71680, while the sum is 42.

The spelling of 21780258180 in words is "twenty-one billion, seven hundred eighty million, two hundred fifty-eight thousand, one hundred eighty".