21094220391 has 8 divisors (see below), whose sum is σ = 29348480640. Its totient is φ = 13451386872.

The previous prime is 21094220363. The next prime is 21094220443. The reversal of 21094220391 is 19302249012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21094220391 - 2⁶ = 21094220327 is a prime.

It is a super-2 number, since 2×21094220391² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21094220311) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152856601 + ... + 152856738.

It is an arithmetic number, because the mean of its divisors is an integer number (3668560080).

Almost surely, 2^21094220391 is an apocalyptic number.

21094220391 is a deficient number, since it is larger than the sum of its proper divisors (8254260249).

21094220391 is a wasteful number, since it uses less digits than its factorization.

21094220391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305713365.

The product of its (nonzero) digits is 7776, while the sum is 33.

The spelling of 21094220391 in words is "twenty-one billion, ninety-four million, two hundred twenty thousand, three hundred ninety-one".