1809121946 has 8 divisors (see below), whose sum is σ = 2873311380. Its totient is φ = 851351488.

The previous prime is 1809121943. The next prime is 1809121949. The reversal of 1809121946 is 6491219081.

It is an interprime number because it is at equal distance from previous prime (1809121943) and next prime (1809121949).

It can be written as a sum of positive squares in 2 ways, for example, as 1737972721 + 71149225 = 41689^2 + 8435^2 .

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

It is not an unprimeable number, because it can be changed into a prime (1809121943) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26604701 + ... + 26604768.

Almost surely, 2^1809121946 is an apocalyptic number.

1809121946 is a deficient number, since it is larger than the sum of its proper divisors (1064189434).

1809121946 is a wasteful number, since it uses less digits than its factorization.

1809121946 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53209488.

The product of its (nonzero) digits is 31104, while the sum is 41.

The square root of 1809121946 is about 42533.7741800560. The cubic root of 1809121946 is about 1218.4918087084.

The spelling of 1809121946 in words is "one billion, eight hundred nine million, one hundred twenty-one thousand, nine hundred forty-six".