21996031 has 4 divisors (see below), whose sum is σ = 22006512. Its totient is φ = 21985552.

The previous prime is 21996001. The next prime is 21996041. The reversal of 21996031 is 13069912.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 21996031 - 2⁷ = 21995903 is a prime.

It is a super-2 number, since 2×21996031² = 967650759505922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21995984 and 21996002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21996001) 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 3 ways as a sum of consecutive naturals, for example, 886 + ... + 6691.

It is an arithmetic number, because the mean of its divisors is an integer number (5501628).

Almost surely, 2^21996031 is an apocalyptic number.

21996031 is a deficient number, since it is larger than the sum of its proper divisors (10481).

21996031 is an equidigital number, since it uses as much as digits as its factorization.

21996031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10480.

The product of its (nonzero) digits is 2916, while the sum is 31.

The square root of 21996031 is about 4689.9926439175. The cubic root of 21996031 is about 280.1870816065.

The spelling of 21996031 in words is "twenty-one million, nine hundred ninety-six thousand, thirty-one".