1809972 has 24 divisors (see below), whose sum is σ = 4692800. Its totient is φ = 603288.

The previous prime is 1809971. The next prime is 1809979. The reversal of 1809972 is 2799081.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1809971) 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, 8272 + ... + 8487.

2^1809972 is an apocalyptic number.

1809972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1809972 is an abundant number, since it is smaller than the sum of its proper divisors (2882828).

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

1809972 is a wasteful number, since it uses less digits than its factorization.

1809972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16772 (or 16764 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 1809972 is about 1345.3519985491. The cubic root of 1809972 is about 121.8682623494.

The spelling of 1809972 in words is "one million, eight hundred nine thousand, nine hundred seventy-two".