123521431 has 8 divisors (see below), whose sum is σ = 140609664. Its totient is φ = 107409720.

The previous prime is 123521423. The next prime is 123521441. The reversal of 123521431 is 134125321.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 123521431 - 2³ = 123521423 is a prime.

It is a super-2 number, since 2×123521431² = 30515087832575522, 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 (123521441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 243861 + ... + 244366.

It is an arithmetic number, because the mean of its divisors is an integer number (17576208).

Almost surely, 2^123521431 is an apocalyptic number.

123521431 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

123521431 is a deficient number, since it is larger than the sum of its proper divisors (17088233).

123521431 is a wasteful number, since it uses less digits than its factorization.

123521431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 488261.

The product of its digits is 720, while the sum is 22.

The square root of 123521431 is about 11114.0195698946. The cubic root of 123521431 is about 498.0207501448.

Adding to 123521431 its reverse (134125321), we get a palindrome (257646752).

The spelling of 123521431 in words is "one hundred twenty-three million, five hundred twenty-one thousand, four hundred thirty-one".