23640981 has 48 divisors (see below), whose sum is σ = 40219200. Its totient is φ = 12241152.

The previous prime is 23640979. The next prime is 23640983. The reversal of 23640981 is 18904632.

It is an interprime number because it is at equal distance from previous prime (23640979) and next prime (23640983).

It is not a de Polignac number, because 23640981 - 2¹ = 23640979 is a prime.

It is a super-2 number, since 2×23640981² = 1117791965284722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23640983) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 170010 + ... + 170148.

It is an arithmetic number, because the mean of its divisors is an integer number (837900).

Almost surely, 2^23640981 is an apocalyptic number.

23640981 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

23640981 is a deficient number, since it is larger than the sum of its proper divisors (16578219).

23640981 is a wasteful number, since it uses less digits than its factorization.

23640981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258 (or 251 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 23640981 is about 4862.1991937805. The cubic root of 23640981 is about 287.0043624163.

The spelling of 23640981 in words is "twenty-three million, six hundred forty thousand, nine hundred eighty-one".