31144012220 has 48 divisors (see below), whose sum is σ = 67273966368. Its totient is φ = 12102163200.

The previous prime is 31144012217. The next prime is 31144012231. The reversal of 31144012220 is 2221044113.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 31144012192 and 31144012201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 450995 + ... + 515445.

It is an arithmetic number, because the mean of its divisors is an integer number (1401540966).

Almost surely, 2^31144012220 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31144012220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33636983184).

31144012220 is an abundant number, since it is smaller than the sum of its proper divisors (36129954148).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

31144012220 is a wasteful number, since it uses less digits than its factorization.

31144012220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65150 (or 65148 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 31144012220 its reverse (2221044113), we get a palindrome (33365056333).

The spelling of 31144012220 in words is "thirty-one billion, one hundred forty-four million, twelve thousand, two hundred twenty".