1821019380 has 48 divisors (see below), whose sum is σ = 5236667520. Its totient is φ = 472480128.

The previous prime is 1821019367. The next prime is 1821019399. The reversal of 1821019380 is 839101281.

It is a super-2 number, since 2×1821019380² = 6632223164671168800, which contains 22 as substring.

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, 407920 + ... + 412359.

It is an arithmetic number, because the mean of its divisors is an integer number (109097240).

Almost surely, 2^1821019380 is an apocalyptic number.

1821019380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1821019380 is an abundant number, since it is smaller than the sum of its proper divisors (3415648140).

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

1821019380 is a wasteful number, since it uses less digits than its factorization.

1821019380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820328 (or 820326 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 33.

The square root of 1821019380 is about 42673.4036608284. The cubic root of 1821019380 is about 1221.1570542274.

The spelling of 1821019380 in words is "one billion, eight hundred twenty-one million, nineteen thousand, three hundred eighty".