1988261 has 4 divisors (see below), whose sum is σ = 2169024. Its totient is φ = 1807500.

The previous prime is 1988257. The next prime is 1988263. The reversal of 1988261 is 1628891.

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 1988261 - 2² = 1988257 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1988263) 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, 90365 + ... + 90386.

It is an arithmetic number, because the mean of its divisors is an integer number (542256).

2^1988261 is an apocalyptic number.

1988261 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1988261 is a deficient number, since it is larger than the sum of its proper divisors (180763).

1988261 is a wasteful number, since it uses less digits than its factorization.

1988261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 180762.

The product of its digits is 6912, while the sum is 35.

The square root of 1988261 is about 1410.0570910428. The cubic root of 1988261 is about 125.7451175730.

The spelling of 1988261 in words is "one million, nine hundred eighty-eight thousand, two hundred sixty-one".