21319767 has 40 divisors (see below), whose sum is σ = 38332800. Its totient is φ = 11535696.

The previous prime is 21319763. The next prime is 21319769. The reversal of 21319767 is 76791312.

It is a happy number.

It is not a de Polignac number, because 21319767 - 2² = 21319763 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21319763) 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 in 39 ways as a sum of consecutive naturals, for example, 9784 + ... + 11762.

It is an arithmetic number, because the mean of its divisors is an integer number (958320).

Almost surely, 2^21319767 is an apocalyptic number.

21319767 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21319767 is a deficient number, since it is larger than the sum of its proper divisors (17013033).

21319767 is a wasteful number, since it uses less digits than its factorization.

21319767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2017 (or 2008 counting only the distinct ones).

The product of its digits is 15876, while the sum is 36.

The square root of 21319767 is about 4617.3333213014. Note that the first 4 decimals coincide. The cubic root of 21319767 is about 277.2857074604.

The spelling of 21319767 in words is "twenty-one million, three hundred nineteen thousand, seven hundred sixty-seven".