1816604640 has 72 divisors (see below), whose sum is σ = 6199168248. Its totient is φ = 484427520.

The previous prime is 1816604639. The next prime is 1816604659. The reversal of 1816604640 is 464066181.

1816604640 is a `hidden beast` number, since 1 + 8 + 1 + 6 + 6 + 0 + 4 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1816604595 and 1816604604.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 629326 + ... + 632205.

It is an arithmetic number, because the mean of its divisors is an integer number (86099559).

Almost surely, 2^1816604640 is an apocalyptic number.

1816604640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1816604640 is an abundant number, since it is smaller than the sum of its proper divisors (4382563608).

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

1816604640 is a wasteful number, since it uses less digits than its factorization.

1816604640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1261552 (or 1261541 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 1816604640 is about 42621.6452052241. The cubic root of 1816604640 is about 1220.1694291253.

The spelling of 1816604640 in words is "one billion, eight hundred sixteen million, six hundred four thousand, six hundred forty".