21829031 has 4 divisors (see below), whose sum is σ = 24947472. Its totient is φ = 18710592.

The previous prime is 21828973. The next prime is 21829091. The reversal of 21829031 is 13092812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21829031 - 2¹⁸ = 21566887 is a prime.

It is a super-2 number, since 2×21829031² = 953013188797922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21829091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1559210 + ... + 1559223.

It is an arithmetic number, because the mean of its divisors is an integer number (6236868).

Almost surely, 2^21829031 is an apocalyptic number.

21829031 is a deficient number, since it is larger than the sum of its proper divisors (3118441).

21829031 is an equidigital number, since it uses as much as digits as its factorization.

21829031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3118440.

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 21829031 is about 4672.1548561665. The cubic root of 21829031 is about 279.4761933250.

The spelling of 21829031 in words is "twenty-one million, eight hundred twenty-nine thousand, thirty-one".