1831221840 has 80 divisors (see below), whose sum is σ = 6487763328. Its totient is φ = 418564608.

The previous prime is 1831221829. The next prime is 1831221851. The reversal of 1831221840 is 481221381.

1831221840 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (1831221829) and next prime (1831221851).

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

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 1831221798 and 1831221807.

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, 543327 + ... + 546686.

Almost surely, 2^1831221840 is an apocalyptic number.

1831221840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1831221840 is an abundant number, since it is smaller than the sum of its proper divisors (4656541488).

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

1831221840 is a wasteful number, since it uses less digits than its factorization.

1831221840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1090036 (or 1090030 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 30.

The square root of 1831221840 is about 42792.7778953412. Note that the first 3 decimals coincide. The cubic root of 1831221840 is about 1223.4333636787.

The spelling of 1831221840 in words is "one billion, eight hundred thirty-one million, two hundred twenty-one thousand, eight hundred forty".