31428081 has 20 divisors (see below), whose sum is σ = 47416512. Its totient is φ = 20743128.

The previous prime is 31428073. The next prime is 31428091. The reversal of 31428081 is 18082413.

It is not a de Polignac number, because 31428081 - 2³ = 31428073 is a prime.

It is a super-2 number, since 2×31428081² = 1975448550685122, which contains 22 as substring.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (31428031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 6460 + ... + 10226.

Almost surely, 2^31428081 is an apocalyptic number.

It is an amenable number.

31428081 is a deficient number, since it is larger than the sum of its proper divisors (15988431).

31428081 is a wasteful number, since it uses less digits than its factorization.

31428081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3882 (or 3873 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 31428081 is about 5606.0753651730. The cubic root of 31428081 is about 315.5774442091.

The spelling of 31428081 in words is "thirty-one million, four hundred twenty-eight thousand, eighty-one".