1983551 has 4 divisors (see below), whose sum is σ = 1988112. Its totient is φ = 1978992.

The previous prime is 1983523. The next prime is 1983559. The reversal of 1983551 is 1553891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1553891 = 43 ⋅36137.

It is a cyclic number.

It is not a de Polignac number, because 1983551 - 2¹⁸ = 1721407 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 (1983559) 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, 1550 + ... + 2523.

It is an arithmetic number, because the mean of its divisors is an integer number (497028).

2^1983551 is an apocalyptic number.

1983551 is a deficient number, since it is larger than the sum of its proper divisors (4561).

1983551 is an equidigital number, since it uses as much as digits as its factorization.

1983551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4560.

The product of its digits is 5400, while the sum is 32.

The square root of 1983551 is about 1408.3859556244. The cubic root of 1983551 is about 125.6457463488.

The spelling of 1983551 in words is "one million, nine hundred eighty-three thousand, five hundred fifty-one".