249642081 has 40 divisors (see below), whose sum is σ = 403307520. Its totient is φ = 152977248.

The previous prime is 249642079. The next prime is 249642091. The reversal of 249642081 is 180246942.

249642081 is a `hidden beast` number, since 2 + 4 + 9 + 642 + 0 + 8 + 1 = 666.

249642081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 249642081 - 2¹ = 249642079 is a prime.

It is a super-2 number, since 2×249642081² = 124642337212021122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (249642091) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 402990 + ... + 403608.

It is an arithmetic number, because the mean of its divisors is an integer number (10082688).

Almost surely, 2^249642081 is an apocalyptic number.

It is an amenable number.

249642081 is a deficient number, since it is larger than the sum of its proper divisors (153665439).

249642081 is a wasteful number, since it uses less digits than its factorization.

249642081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1027 (or 1018 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The square root of 249642081 is about 15800.0658542931. The cubic root of 249642081 is about 629.6597482420.

The spelling of 249642081 in words is "two hundred forty-nine million, six hundred forty-two thousand, eighty-one".