21160621357 has 4 divisors (see below), whose sum is σ = 21302639100. Its totient is φ = 21018603616.

The previous prime is 21160621351. The next prime is 21160621367. The reversal of 21160621357 is 75312606112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14114865636 + 7045755721 = 118806^2 + 83939^2 .

It is a cyclic number.

It is not a de Polignac number, because 21160621357 - 2³¹ = 19013137709 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 (21160621351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71008648 + ... + 71008945.

It is an arithmetic number, because the mean of its divisors is an integer number (5325659775).

Almost surely, 2^21160621357 is an apocalyptic number.

It is an amenable number.

21160621357 is a deficient number, since it is larger than the sum of its proper divisors (142017743).

21160621357 is a wasteful number, since it uses less digits than its factorization.

21160621357 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142017742.

The product of its (nonzero) digits is 15120, while the sum is 34.

The spelling of 21160621357 in words is "twenty-one billion, one hundred sixty million, six hundred twenty-one thousand, three hundred fifty-seven".