21273906851 has 8 divisors (see below), whose sum is σ = 21365367408. Its totient is φ = 21182500000.

The previous prime is 21273906803. The next prime is 21273906859. The reversal of 21273906851 is 15860937212.

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

It is a cyclic number.

It is not a de Polignac number, because 21273906851 - 2³⁴ = 4094037667 is a prime.

It is a super-2 number, since 2×21273906851² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21273906859) 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, 917501 + ... + 940401.

It is an arithmetic number, because the mean of its divisors is an integer number (2670670926).

Almost surely, 2^21273906851 is an apocalyptic number.

21273906851 is a deficient number, since it is larger than the sum of its proper divisors (91460557).

21273906851 is a wasteful number, since it uses less digits than its factorization.

21273906851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26853.

The product of its (nonzero) digits is 181440, while the sum is 44.

The spelling of 21273906851 in words is "twenty-one billion, two hundred seventy-three million, nine hundred six thousand, eight hundred fifty-one".