21120001667 has 2 divisors, whose sum is σ = 21120001668. Its totient is φ = 21120001666.

The previous prime is 21120001619. The next prime is 21120001673. The reversal of 21120001667 is 76610002112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21120001667 - 2⁸ = 21120001411 is a prime.

It is not a weakly prime, because it can be changed into another prime (21120001267) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10560000833 + 10560000834.

It is an arithmetic number, because the mean of its divisors is an integer number (10560000834).

Almost surely, 2^21120001667 is an apocalyptic number.

21120001667 is a deficient number, since it is larger than the sum of its proper divisors (1).

21120001667 is an equidigital number, since it uses as much as digits as its factorization.

21120001667 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1008, while the sum is 26.

Adding to 21120001667 its reverse (76610002112), we get a palindrome (97730003779).

The spelling of 21120001667 in words is "twenty-one billion, one hundred twenty million, one thousand, six hundred sixty-seven".