21475965775 has 12 divisors (see below), whose sum is σ = 29051124984. Its totient is φ = 15618884000.

The previous prime is 21475965713. The next prime is 21475965779. The reversal of 21475965775 is 57756957412.

It is not a de Polignac number, because 21475965775 - 2¹⁵ = 21475933007 is a prime.

It is a super-2 number, since 2×21475965775² (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 (21475965779) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39046936 + ... + 39047485.

It is an arithmetic number, because the mean of its divisors is an integer number (2420927082).

Almost surely, 2^21475965775 is an apocalyptic number.

21475965775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21475965775 is a deficient number, since it is larger than the sum of its proper divisors (7575159209).

21475965775 is a wasteful number, since it uses less digits than its factorization.

21475965775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78094442 (or 78094437 counting only the distinct ones).

The product of its digits is 18522000, while the sum is 58.

The spelling of 21475965775 in words is "twenty-one billion, four hundred seventy-five million, nine hundred sixty-five thousand, seven hundred seventy-five".