21057637361 has 8 divisors (see below), whose sum is σ = 21128182848. Its totient is φ = 20987190000.

The previous prime is 21057637277. The next prime is 21057637369. The reversal of 21057637361 is 16373675012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21057637361 - 2¹⁸ = 21057375217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21057637369) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 418676 + ... + 466266.

It is an arithmetic number, because the mean of its divisors is an integer number (2641022856).

Almost surely, 2^21057637361 is an apocalyptic number.

It is an amenable number.

21057637361 is a deficient number, since it is larger than the sum of its proper divisors (70545487).

21057637361 is a wasteful number, since it uses less digits than its factorization.

21057637361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49063.

The product of its (nonzero) digits is 158760, while the sum is 41.

The spelling of 21057637361 in words is "twenty-one billion, fifty-seven million, six hundred thirty-seven thousand, three hundred sixty-one".