2645981 has 8 divisors (see below), whose sum is σ = 2927064. Its totient is φ = 2376000.

The previous prime is 2645977. The next prime is 2645987. The reversal of 2645981 is 1895462.

It can be written as a sum of positive squares in 4 ways, for example, as 1229881 + 1416100 = 1109^2 + 1190^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2645981 - 2² = 2645977 is a prime.

It is a super-2 number, since 2×2645981² = 14002430904722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2645987) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2270 + ... + 3231.

It is an arithmetic number, because the mean of its divisors is an integer number (365883).

2^2645981 is an apocalyptic number.

It is an amenable number.

2645981 is a deficient number, since it is larger than the sum of its proper divisors (281083).

2645981 is a wasteful number, since it uses less digits than its factorization.

2645981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5551.

The product of its digits is 17280, while the sum is 35.

The square root of 2645981 is about 1626.6471651836. The cubic root of 2645981 is about 138.3127577017.

The spelling of 2645981 in words is "two million, six hundred forty-five thousand, nine hundred eighty-one".