21091775476 has 12 divisors (see below), whose sum is σ = 36927301572. Its totient is φ = 10541117888.

The previous prime is 21091775459. The next prime is 21091775477. The reversal of 21091775476 is 67457719012.

It can be written as a sum of positive squares in 2 ways, for example, as 19258223076 + 1833552400 = 138774^2 + 42820^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21091775477) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1182505 + ... + 1200208.

It is an arithmetic number, because the mean of its divisors is an integer number (3077275131).

Almost surely, 2^21091775476 is an apocalyptic number.

It is an amenable number.

21091775476 is a deficient number, since it is larger than the sum of its proper divisors (15835526096).

21091775476 is a wasteful number, since it uses less digits than its factorization.

21091775476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2384930 (or 2384928 counting only the distinct ones).

The product of its (nonzero) digits is 740880, while the sum is 49.

The spelling of 21091775476 in words is "twenty-one billion, ninety-one million, seven hundred seventy-five thousand, four hundred seventy-six".