21178368260741 has 4 divisors (see below), whose sum is σ = 21190490968992. Its totient is φ = 21166245552492.

The previous prime is 21178368260671. The next prime is 21178368260783. The reversal of 21178368260741 is 14706286387112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21178368260741 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21178368260341) 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, 6061351505 + ... + 6061354998.

It is an arithmetic number, because the mean of its divisors is an integer number (5297622742248).

Almost surely, 2^{21178368260741} is an apocalyptic number.

It is an amenable number.

21178368260741 is a deficient number, since it is larger than the sum of its proper divisors (12122708251).

21178368260741 is a wasteful number, since it uses less digits than its factorization.

21178368260741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12122708250.

The product of its (nonzero) digits is 5419008, while the sum is 56.

The spelling of 21178368260741 in words is "twenty-one trillion, one hundred seventy-eight billion, three hundred sixty-eight million, two hundred sixty thousand, seven hundred forty-one".