31440221423 has 4 divisors (see below), whose sum is σ = 33858700008. Its totient is φ = 29021742840.

The previous prime is 31440221411. The next prime is 31440221441. The reversal of 31440221423 is 32412204413.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32412204413 = 28297 ⋅1145429.

It is a cyclic number.

It is not a de Polignac number, because 31440221423 - 2²⁰ = 31439172847 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 31440221392 and 31440221401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31440226423) 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, 1209239273 + ... + 1209239298.

It is an arithmetic number, because the mean of its divisors is an integer number (8464675002).

Almost surely, 2^31440221423 is an apocalyptic number.

31440221423 is a deficient number, since it is larger than the sum of its proper divisors (2418478585).

31440221423 is a wasteful number, since it uses less digits than its factorization.

31440221423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2418478584.

The product of its (nonzero) digits is 4608, while the sum is 26.

Adding to 31440221423 its reverse (32412204413), we get a palindrome (63852425836).

The spelling of 31440221423 in words is "thirty-one billion, four hundred forty million, two hundred twenty-one thousand, four hundred twenty-three".