31423340 has 48 divisors (see below), whose sum is σ = 74817120. Its totient is φ = 10990080.

The previous prime is 31423339. The next prime is 31423351. The reversal of 31423340 is 4332413.

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

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, 1760 + ... + 8120.

It is an arithmetic number, because the mean of its divisors is an integer number (1558690).

Almost surely, 2^31423340 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 31423340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37408560).

31423340 is an abundant number, since it is smaller than the sum of its proper divisors (43393780).

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

31423340 is a wasteful number, since it uses less digits than its factorization.

31423340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6402 (or 6400 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 31423340 is about 5605.6525043923. The cubic root of 31423340 is about 315.5615748776.

Adding to 31423340 its reverse (4332413), we get a palindrome (35755753).

The spelling of 31423340 in words is "thirty-one million, four hundred twenty-three thousand, three hundred forty".