31406220 has 72 divisors (see below), whose sum is σ = 95986800. Its totient is φ = 8311680.

The previous prime is 31406197. The next prime is 31406233. The reversal of 31406220 is 2260413.

It is a happy number.

31406220 is a `hidden beast` number, since 3 + 1 + 40 + 622 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 31406193 and 31406202.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26235 + ... + 27405.

It is an arithmetic number, because the mean of its divisors is an integer number (1333150).

Almost surely, 2^31406220 is an apocalyptic number.

31406220 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 31406220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (47993400).

31406220 is an abundant number, since it is smaller than the sum of its proper divisors (64580580).

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

31406220 is a wasteful number, since it uses less digits than its factorization.

31406220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1335 (or 1330 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 31406220 is about 5604.1252662659. The cubic root of 31406220 is about 315.5042565959.

Adding to 31406220 its reverse (2260413), we get a palindrome (33666633).

It can be divided in two parts, 31406 and 220, that added together give a triangular number (31626 = T₂₅₁).

The spelling of 31406220 in words is "thirty-one million, four hundred six thousand, two hundred twenty".