21266761396 has 6 divisors (see below), whose sum is σ = 37216832450. Its totient is φ = 10633380696.

The previous prime is 21266761381. The next prime is 21266761409. The reversal of 21266761396 is 69316766212.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 21054010000 + 212751396 = 145100^2 + 14586^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2658345171 + ... + 2658345178.

Almost surely, 2^21266761396 is an apocalyptic number.

It is an amenable number.

21266761396 is a deficient number, since it is larger than the sum of its proper divisors (15950071054).

21266761396 is a wasteful number, since it uses less digits than its factorization.

21266761396 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5316690353 (or 5316690351 counting only the distinct ones).

The product of its digits is 979776, while the sum is 49.

The spelling of 21266761396 in words is "twenty-one billion, two hundred sixty-six million, seven hundred sixty-one thousand, three hundred ninety-six".