31000001 has 4 divisors (see below), whose sum is σ = 32631600. Its totient is φ = 29368404.

The previous prime is 30999989. The next prime is 31000003. The reversal of 31000001 is 10000013.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10000013 = 421 ⋅23753.

It is a cyclic number.

It is not a de Polignac number, because 31000001 - 2⁶ = 30999937 is a prime.

It is a super-2 number, since 2×31000001² = 1922000124000002, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31000003) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 815771 + ... + 815808.

It is an arithmetic number, because the mean of its divisors is an integer number (8157900).

Almost surely, 2^31000001 is an apocalyptic number.

It is an amenable number.

31000001 is a deficient number, since it is larger than the sum of its proper divisors (1631599).

31000001 is a wasteful number, since it uses less digits than its factorization.

31000001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1631598.

The product of its (nonzero) digits is 3, while the sum is 5.

The square root of 31000001 is about 5567.7644526327. The cubic root of 31000001 is about 314.1380686170.

Adding to 31000001 its reverse (10000013), we get a palindrome (41000014).

It can be divided in two parts, 3 and 1000001, that multiplied together give a palindrome (3000003).

The spelling of 31000001 in words is "thirty-one million, one", and thus it is an aban number and an uban number.