21155367774 has 8 divisors (see below), whose sum is σ = 42310735560. Its totient is φ = 7051789256.

The previous prime is 21155367743. The next prime is 21155367781. The reversal of 21155367774 is 47776355112.

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

21155367774 is an admirable number.

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, 1762947309 + ... + 1762947320.

It is an arithmetic number, because the mean of its divisors is an integer number (5288841945).

Almost surely, 2^21155367774 is an apocalyptic number.

21155367774 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21155367774 is a wasteful number, since it uses less digits than its factorization.

21155367774 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3525894634.

The product of its digits is 1234800, while the sum is 48.

The spelling of 21155367774 in words is "twenty-one billion, one hundred fifty-five million, three hundred sixty-seven thousand, seven hundred seventy-four".