23481781 has 6 divisors (see below), whose sum is σ = 24547670. Its totient is φ = 22460328.

The previous prime is 23481763. The next prime is 23481797. The reversal of 23481781 is 18718432.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 23328900 + 152881 = 4830^2 + 391^2 .

It is not a de Polignac number, because 23481781 - 2¹³ = 23473589 is a prime.

It is a super-2 number, since 2×23481781² = 1102788077863922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23481721) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21666 + ... + 22723.

Almost surely, 2^23481781 is an apocalyptic number.

It is an amenable number.

23481781 is a deficient number, since it is larger than the sum of its proper divisors (1065889).

23481781 is an equidigital number, since it uses as much as digits as its factorization.

23481781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44435 (or 44412 counting only the distinct ones).

The product of its digits is 10752, while the sum is 34.

The square root of 23481781 is about 4845.8003466920. The cubic root of 23481781 is about 286.3586751349.

The spelling of 23481781 in words is "twenty-three million, four hundred eighty-one thousand, seven hundred eighty-one".