31428216 has 32 divisors (see below), whose sum is σ = 87301200. Its totient is φ = 10476000.

The previous prime is 31428191. The next prime is 31428253. The reversal of 31428216 is 61282413.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits.

It is a self number, because there is not a number n which added to its sum of digits gives 31428216.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 72535 + ... + 72966.

Almost surely, 2^31428216 is an apocalyptic number.

31428216 is a gapful number since it is divisible by the number (36) formed by its first and last digit.

It is an amenable number.

31428216 is an abundant number, since it is smaller than the sum of its proper divisors (55872984).

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

31428216 is a wasteful number, since it uses less digits than its factorization.

31428216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 145516 (or 145506 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 31428216 is about 5606.0874056689. The cubic root of 31428216 is about 315.5778960650.

The spelling of 31428216 in words is "thirty-one million, four hundred twenty-eight thousand, two hundred sixteen".