21266446652 has 12 divisors (see below), whose sum is σ = 40599580056. Its totient is φ = 9666566640.

The previous prime is 21266446609. The next prime is 21266446681. The reversal of 21266446652 is 25664466212.

It is a Harshad number since it is a multiple of its sum of digits (44), and also a Moran number because the ratio is a prime number: 483328333 = 21266446652 / (2 + 1 + 2 + 6 + 6 + 4 + 4 + 6 + 6 + 5 + 2).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 241664123 + ... + 241664210.

It is an arithmetic number, because the mean of its divisors is an integer number (3383298338).

Almost surely, 2^21266446652 is an apocalyptic number.

21266446652 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21266446652 is a deficient number, since it is larger than the sum of its proper divisors (19333133404).

21266446652 is a wasteful number, since it uses less digits than its factorization.

21266446652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 483328348 (or 483328346 counting only the distinct ones).

The product of its digits is 829440, while the sum is 44.

The spelling of 21266446652 in words is "twenty-one billion, two hundred sixty-six million, four hundred forty-six thousand, six hundred fifty-two".