1898721 has 20 divisors (see below), whose sum is σ = 3095664. Its totient is φ = 1150200.

The previous prime is 1898711. The next prime is 1898737. The reversal of 1898721 is 1278981.

It is not a de Polignac number, because 1898721 - 2⁷ = 1898593 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not an unprimeable number, because it can be changed into a prime (1898711) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 175 + ... + 1956.

2^1898721 is an apocalyptic number.

1898721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1898721 is a deficient number, since it is larger than the sum of its proper divisors (1196943).

1898721 is a wasteful number, since it uses less digits than its factorization.

1898721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2154 (or 2145 counting only the distinct ones).

The product of its digits is 8064, while the sum is 36.

The square root of 1898721 is about 1377.9408550442. The cubic root of 1898721 is about 123.8284351243.

The spelling of 1898721 in words is "one million, eight hundred ninety-eight thousand, seven hundred twenty-one".