31428020 has 24 divisors (see below), whose sum is σ = 71076264. Its totient is φ = 11604096.

The previous prime is 31428013. The next prime is 31428029. The reversal of 31428020 is 2082413.

It can be written as a sum of positive squares in 4 ways, for example, as 784 + 31427236 = 28^2 + 5606^2 .

It is a super-3 number, since 3×31428020³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

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 = 31427983 and 31428001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (31428029) 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, 60179 + ... + 60698.

It is an arithmetic number, because the mean of its divisors is an integer number (2961511).

Almost surely, 2^31428020 is an apocalyptic number.

It is an amenable number.

31428020 is an abundant number, since it is smaller than the sum of its proper divisors (39648244).

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

31428020 is a wasteful number, since it uses less digits than its factorization.

31428020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120899 (or 120897 counting only the distinct ones).

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

The square root of 31428020 is about 5606.0699246442. The cubic root of 31428020 is about 315.5772400367.

The spelling of 31428020 in words is "thirty-one million, four hundred twenty-eight thousand, twenty".