21349667 has 2 divisors, whose sum is σ = 21349668. Its totient is φ = 21349666.

The previous prime is 21349663. The next prime is 21349687. The reversal of 21349667 is 76694312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21349667 - 2² = 21349663 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21349667.

It is not a weakly prime, because it can be changed into another prime (21349661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10674833 + 10674834.

It is an arithmetic number, because the mean of its divisors is an integer number (10674834).

Almost surely, 2^21349667 is an apocalyptic number.

21349667 is a deficient number, since it is larger than the sum of its proper divisors (1).

21349667 is an equidigital number, since it uses as much as digits as its factorization.

21349667 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 38.

The square root of 21349667 is about 4620.5699864844. The cubic root of 21349667 is about 277.4152737580.

The spelling of 21349667 in words is "twenty-one million, three hundred forty-nine thousand, six hundred sixty-seven".