981621 has 12 divisors (see below), whose sum is σ = 1467180. Its totient is φ = 631680.

The previous prime is 981601. The next prime is 981623. The reversal of 981621 is 126189.

It can be written as a sum of positive squares in 2 ways, for example, as 476100 + 505521 = 690^2 + 711^2 .

It is not a de Polignac number, because 981621 - 2⁷ = 981493 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 (981623) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1620 + ... + 2141.

It is an arithmetic number, because the mean of its divisors is an integer number (122265).

2⁹⁸¹⁶²¹ is an apocalyptic number.

It is an amenable number.

981621 is a deficient number, since it is larger than the sum of its proper divisors (485559).

981621 is a wasteful number, since it uses less digits than its factorization.

981621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3796 (or 3793 counting only the distinct ones).

The product of its digits is 864, while the sum is 27.

The square root of 981621 is about 990.7678840172. The cubic root of 981621 is about 99.3835746725.

The spelling of 981621 in words is "nine hundred eighty-one thousand, six hundred twenty-one".