21700667533 has 2 divisors, whose sum is σ = 21700667534. Its totient is φ = 21700667532.

The previous prime is 21700667531. The next prime is 21700667551. The reversal of 21700667533 is 33576600712.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16021990084 + 5678677449 = 126578^2 + 75357^2 .

It is a cyclic number.

It is not a de Polignac number, because 21700667533 - 2¹ = 21700667531 is a prime.

Together with 21700667531, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21700667531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10850333766 + 10850333767.

It is an arithmetic number, because the mean of its divisors is an integer number (10850333767).

Almost surely, 2^21700667533 is an apocalyptic number.

It is an amenable number.

21700667533 is a deficient number, since it is larger than the sum of its proper divisors (1).

21700667533 is an equidigital number, since it uses as much as digits as its factorization.

21700667533 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 158760, while the sum is 40.

The spelling of 21700667533 in words is "twenty-one billion, seven hundred million, six hundred sixty-seven thousand, five hundred thirty-three".