21203121967 has 2 divisors, whose sum is σ = 21203121968. Its totient is φ = 21203121966.

The previous prime is 21203121931. The next prime is 21203122009. The reversal of 21203121967 is 76912130212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21203121967 - 2¹¹ = 21203119919 is a prime.

It is a super-2 number, since 2×21203121967² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21203124967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601560983 + 10601560984.

It is an arithmetic number, because the mean of its divisors is an integer number (10601560984).

Almost surely, 2^21203121967 is an apocalyptic number.

21203121967 is a deficient number, since it is larger than the sum of its proper divisors (1).

21203121967 is an equidigital number, since it uses as much as digits as its factorization.

21203121967 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 34.

The spelling of 21203121967 in words is "twenty-one billion, two hundred three million, one hundred twenty-one thousand, nine hundred sixty-seven".