1820387680 has 24 divisors (see below), whose sum is σ = 4300666272. Its totient is φ = 728155008.

The previous prime is 1820387677. The next prime is 1820387687. The reversal of 1820387680 is 867830281.

It is a happy number.

It is a super-2 number, since 2×1820387680² = 6627622610991564800, which contains 22 as substring.

It is a Smith number, since the sum of its digits (43) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820387687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5688552 + ... + 5688871.

It is an arithmetic number, because the mean of its divisors is an integer number (179194428).

Almost surely, 2^1820387680 is an apocalyptic number.

1820387680 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1820387680 is an abundant number, since it is smaller than the sum of its proper divisors (2480278592).

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

1820387680 is a wasteful number, since it uses less digits than its factorization.

1820387680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11377438 (or 11377430 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 43.

The square root of 1820387680 is about 42666.0014531477. The cubic root of 1820387680 is about 1221.0158340341.

The spelling of 1820387680 in words is "one billion, eight hundred twenty million, three hundred eighty-seven thousand, six hundred eighty".