231148781 has 4 divisors (see below), whose sum is σ = 241198752. Its totient is φ = 221098812.

The previous prime is 231148777. The next prime is 231148793. The reversal of 231148781 is 187841132.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 231148781 - 2² = 231148777 is a prime.

It is a super-2 number, since 2×231148781² = 106859517915571922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (231148721) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5024951 + ... + 5024996.

It is an arithmetic number, because the mean of its divisors is an integer number (60299688).

Almost surely, 2^231148781 is an apocalyptic number.

It is an amenable number.

231148781 is a deficient number, since it is larger than the sum of its proper divisors (10049971).

231148781 is a wasteful number, since it uses less digits than its factorization.

231148781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10049970.

The product of its digits is 10752, while the sum is 35.

The square root of 231148781 is about 15203.5779012705. The cubic root of 231148781 is about 613.7109457578.

The spelling of 231148781 in words is "two hundred thirty-one million, one hundred forty-eight thousand, seven hundred eighty-one".