2497981 has 8 divisors (see below), whose sum is σ = 2586584. Its totient is φ = 2410560.

The previous prime is 2497967. The next prime is 2497991. The reversal of 2497981 is 1897942.

It can be written as a sum of positive squares in 4 ways, for example, as 220900 + 2277081 = 470^2 + 1509^2 .

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

It is a 5-Lehmer number, since φ(2497981) divides (2497981-1)⁵.

It is a cyclic number.

It is not a de Polignac number, because 2497981 - 2¹³ = 2489789 is a prime.

It is a super-2 number, since 2×2497981² = 12479818152722, which contains 22 as substring.

It is the 1581-st Hogben number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2497931) by changing a digit.

It is a nontrivial repunit in base 1580.

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 7 ways as a sum of consecutive naturals, for example, 6511 + ... + 6883.

It is an arithmetic number, because the mean of its divisors is an integer number (323323).

2^2497981 is an apocalyptic number.

It is an amenable number.

2497981 is a deficient number, since it is larger than the sum of its proper divisors (88603).

2497981 is a wasteful number, since it uses less digits than its factorization.

2497981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 591.

The product of its digits is 36288, while the sum is 40.

The square root of 2497981 is about 1580.5002372667. The cubic root of 2497981 is about 135.6843349287.

The spelling of 2497981 in words is "two million, four hundred ninety-seven thousand, nine hundred eighty-one".