1902721 has 4 divisors (see below), whose sum is σ = 1985472. Its totient is φ = 1819972.

The previous prime is 1902671. The next prime is 1902737. The reversal of 1902721 is 1272091.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1902721 - 2⁹ = 1902209 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1902692 and 1902701.

It is not an unprimeable number, because it can be changed into a prime (1902221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 41341 + ... + 41386.

It is an arithmetic number, because the mean of its divisors is an integer number (496368).

2^1902721 is an apocalyptic number.

It is an amenable number.

1902721 is a deficient number, since it is larger than the sum of its proper divisors (82751).

1902721 is an equidigital number, since it uses as much as digits as its factorization.

1902721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82750.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 1902721 is about 1379.3915325244. The cubic root of 1902721 is about 123.9153298154.

The spelling of 1902721 in words is "one million, nine hundred two thousand, seven hundred twenty-one".