21475844767 has 16 divisors (see below), whose sum is σ = 23316334272. Its totient is φ = 19662531840.

The previous prime is 21475844729. The next prime is 21475844773. The reversal of 21475844767 is 76744857412.

It is a cyclic number.

It is not a de Polignac number, because 21475844767 - 2⁷ = 21475844639 is a prime.

It is a super-2 number, since 2×21475844767² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21475844867) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2430217 + ... + 2439037.

It is an arithmetic number, because the mean of its divisors is an integer number (1457270892).

Almost surely, 2^21475844767 is an apocalyptic number.

21475844767 is a deficient number, since it is larger than the sum of its proper divisors (1840489505).

21475844767 is a wasteful number, since it uses less digits than its factorization.

21475844767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10338.

The product of its digits is 10536960, while the sum is 55.

The spelling of 21475844767 in words is "twenty-one billion, four hundred seventy-five million, eight hundred forty-four thousand, seven hundred sixty-seven".