31320220416 has 72 divisors (see below), whose sum is σ = 83578178880. Its totient is φ = 10412430336.

The previous prime is 31320220411. The next prime is 31320220423. The reversal of 31320220416 is 61402202313.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (31320220411) 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, 237271 + ... + 344873.

It is an arithmetic number, because the mean of its divisors is an integer number (1160808040).

Almost surely, 2^31320220416 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 31320220416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41789089440).

31320220416 is an abundant number, since it is smaller than the sum of its proper divisors (52257958464).

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

31320220416 is a wasteful number, since it uses less digits than its factorization.

31320220416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108001 (or 107987 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 31320220416 its reverse (61402202313), we get a palindrome (92722422729).

The spelling of 31320220416 in words is "thirty-one billion, three hundred twenty million, two hundred twenty thousand, four hundred sixteen".