1820820901 has 8 divisors (see below), whose sum is σ = 1917149600. Its totient is φ = 1724541840.

The previous prime is 1820820899. The next prime is 1820820917. The reversal of 1820820901 is 1090280281.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1820820901 - 2¹ = 1820820899 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1820820931) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 80986 + ... + 100996.

It is an arithmetic number, because the mean of its divisors is an integer number (239643700).

Almost surely, 2^1820820901 is an apocalyptic number.

It is an amenable number.

1820820901 is a deficient number, since it is larger than the sum of its proper divisors (96328699).

1820820901 is a wasteful number, since it uses less digits than its factorization.

1820820901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24819.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 1820820901 is about 42671.0780388778. The cubic root of 1820820901 is about 1221.1126866167.

The spelling of 1820820901 in words is "one billion, eight hundred twenty million, eight hundred twenty thousand, nine hundred one".