21916432887001 has 27 divisors (see below), whose sum is σ = 23333625871101. Its totient is φ = 20584064227104.

The previous prime is 21916432886963. The next prime is 21916432887029. The reversal of 21916432887001 is 10078823461912.

The square root of 21916432887001 is 4681499.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 4664239299225 + 17252193587776 = 2159685^2 + 4153576^2 .

It is not a de Polignac number, because 21916432887001 - 2¹⁵ = 21916432854233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21916432887001.

It is not an unprimeable number, because it can be changed into a prime (21916432887031) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 5023246246 + ... + 5023250608.

Almost surely, 2^{21916432887001} is an apocalyptic number.

21916432887001 is the 4681499-th square number.

21916432887001 is the 2340750-th centered octagonal number.

It is an amenable number.

21916432887001 is a deficient number, since it is larger than the sum of its proper divisors (1417192984100).

21916432887001 is an frugal number, since it uses more digits than its factorization.

21916432887001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8858 (or 4429 counting only the distinct ones).

The product of its (nonzero) digits is 1161216, while the sum is 52.

The spelling of 21916432887001 in words is "twenty-one trillion, nine hundred sixteen billion, four hundred thirty-two million, eight hundred eighty-seven thousand, one".