1821805481 has 16 divisors (see below), whose sum is σ = 1955870400. Its totient is φ = 1691731008.

The previous prime is 1821805457. The next prime is 1821805501. The reversal of 1821805481 is 1845081281.

It is a cyclic number.

It is not a de Polignac number, because 1821805481 - 2⁶ = 1821805417 is a prime.

It is a super-2 number, since 2×1821805481² = 6637950421203282722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1821805421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 415955 + ... + 420311.

It is an arithmetic number, because the mean of its divisors is an integer number (122241900).

Almost surely, 2^1821805481 is an apocalyptic number.

It is an amenable number.

1821805481 is a deficient number, since it is larger than the sum of its proper divisors (134064919).

1821805481 is a wasteful number, since it uses less digits than its factorization.

1821805481 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4808.

The product of its (nonzero) digits is 20480, while the sum is 38.

The square root of 1821805481 is about 42682.6133337686. The cubic root of 1821805481 is about 1221.3327460577.

The spelling of 1821805481 in words is "one billion, eight hundred twenty-one million, eight hundred five thousand, four hundred eighty-one".