21273906803 has 2 divisors, whose sum is σ = 21273906804. Its totient is φ = 21273906802.

The previous prime is 21273906791. The next prime is 21273906859. The reversal of 21273906803 is 30860937212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21273906803 - 2¹² = 21273902707 is a prime.

It is a super-2 number, since 2×21273906803² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21273900803) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10636953401 + 10636953402.

It is an arithmetic number, because the mean of its divisors is an integer number (10636953402).

Almost surely, 2^21273906803 is an apocalyptic number.

21273906803 is a deficient number, since it is larger than the sum of its proper divisors (1).

21273906803 is an equidigital number, since it uses as much as digits as its factorization.

21273906803 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 108864, while the sum is 41.

The spelling of 21273906803 in words is "twenty-one billion, two hundred seventy-three million, nine hundred six thousand, eight hundred three".