21194031 has 4 divisors (see below), whose sum is σ = 28258712. Its totient is φ = 14129352.

The previous prime is 21194029. The next prime is 21194077. The reversal of 21194031 is 13049112.

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

It is not a de Polignac number, because 21194031 - 2¹ = 21194029 is a prime.

It is a super-2 number, since 2×21194031² = 898373900057922, 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 = 21193989 and 21194007.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21194021) 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, 3532336 + ... + 3532341.

It is an arithmetic number, because the mean of its divisors is an integer number (7064678).

Almost surely, 2^21194031 is an apocalyptic number.

21194031 is a deficient number, since it is larger than the sum of its proper divisors (7064681).

21194031 is an equidigital number, since it uses as much as digits as its factorization.

21194031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7064680.

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 21194031 is about 4603.6975356772. The cubic root of 21194031 is about 276.7395232392.

The spelling of 21194031 in words is "twenty-one million, one hundred ninety-four thousand, thirty-one".