249124681 has 16 divisors (see below), whose sum is σ = 286908048. Its totient is φ = 214272000.

The previous prime is 249124679. The next prime is 249124697. The reversal of 249124681 is 186421942.

249124681 is a nontrivial binomial coefficient, being equal to C(22322, 2).

It can be written as a sum of positive squares in 8 ways, for example, as 1345600 + 247779081 = 1160^2 + 15741^2 .

It is a 4-Lehmer number, since φ(249124681) divides (249124681-1)⁴.

It is a cyclic number.

It is not a de Polignac number, because 249124681 - 2¹ = 249124679 is a prime.

It is a super-2 number, since 2×249124681² = 124126213366703522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 249124681.

It is not an unprimeable number, because it can be changed into a prime (249122681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16741 + ... + 27901.

It is an arithmetic number, because the mean of its divisors is an integer number (17931753).

Almost surely, 2^249124681 is an apocalyptic number.

249124681 is the 22321-st triangular number and also the 11161-st hexagonal number.

249124681 is the 7441-st centered nonagonal number.

It is an amenable number.

249124681 is a deficient number, since it is larger than the sum of its proper divisors (37783367).

249124681 is a wasteful number, since it uses less digits than its factorization.

249124681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11292.

The product of its digits is 27648, while the sum is 37.

The square root of 249124681 is about 15783.6840122957. The cubic root of 249124681 is about 629.2244433139.

It can be divided in two parts, 2491 and 24681, that added together give a palindrome (27172).

The spelling of 249124681 in words is "two hundred forty-nine million, one hundred twenty-four thousand, six hundred eighty-one".