981620 has 12 divisors (see below), whose sum is σ = 2061444. Its totient is φ = 392640.

The previous prime is 981601. The next prime is 981623. The reversal of 981620 is 26189.

It can be written as a sum of positive squares in 2 ways, for example, as 425104 + 556516 = 652^2 + 746^2 .

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 981620.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (981623) by changing a digit.

981620 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24521 + ... + 24560.

It is an arithmetic number, because the mean of its divisors is an integer number (171787).

2⁹⁸¹⁶²⁰ is an apocalyptic number.

It is an amenable number.

981620 is an abundant number, since it is smaller than the sum of its proper divisors (1079824).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

981620 is a wasteful number, since it uses less digits than its factorization.

981620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49090 (or 49088 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 981620 is about 990.7673793580. The cubic root of 981620 is about 99.3835409243.

The spelling of 981620 in words is "nine hundred eighty-one thousand, six hundred twenty".