1821421375 has 16 divisors (see below), whose sum is σ = 2295656064. Its totient is φ = 1442700000.

The previous prime is 1821421369. The next prime is 1821421397. The reversal of 1821421375 is 5731241281.

It is not a de Polignac number, because 1821421375 - 2⁹ = 1821420863 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1821421375.

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, 59511 + ... + 84760.

It is an arithmetic number, because the mean of its divisors is an integer number (143478504).

Almost surely, 2^1821421375 is an apocalyptic number.

1821421375 is a deficient number, since it is larger than the sum of its proper divisors (474234689).

1821421375 is a wasteful number, since it uses less digits than its factorization.

1821421375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 144387 (or 144377 counting only the distinct ones).

The product of its digits is 13440, while the sum is 34.

The square root of 1821421375 is about 42678.1135360972. The cubic root of 1821421375 is about 1221.2469055341.

The spelling of 1821421375 in words is "one billion, eight hundred twenty-one million, four hundred twenty-one thousand, three hundred seventy-five".