21261082767 has 8 divisors (see below), whose sum is σ = 28349826480. Its totient is φ = 14173197120.

The previous prime is 21261082763. The next prime is 21261082789. The reversal of 21261082767 is 76728016212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21261082767 - 2² = 21261082763 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21261082763) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 154284 + ... + 257537.

It is an arithmetic number, because the mean of its divisors is an integer number (3543728310).

Almost surely, 2^21261082767 is an apocalyptic number.

21261082767 is a deficient number, since it is larger than the sum of its proper divisors (7088743713).

21261082767 is a wasteful number, since it uses less digits than its factorization.

21261082767 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429033.

The product of its (nonzero) digits is 112896, while the sum is 42.

Adding to 21261082767 its reverse (76728016212), we get a palindrome (97989098979).

The spelling of 21261082767 in words is "twenty-one billion, two hundred sixty-one million, eighty-two thousand, seven hundred sixty-seven".