21783609371738 has 8 divisors (see below), whose sum is σ = 32687620047732. Its totient is φ = 10887736022496.

The previous prime is 21783609371723. The next prime is 21783609371749. The reversal of 21783609371738 is 83717390638712.

It can be written as a sum of positive squares in 2 ways, for example, as 16893686497249 + 4889922874489 = 4110193^2 + 2211317^2 .

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

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, 2034324995 + ... + 2034335702.

Almost surely, 2^{21783609371738} is an apocalyptic number.

21783609371738 is a deficient number, since it is larger than the sum of its proper divisors (10904010675994).

21783609371738 is a wasteful number, since it uses less digits than its factorization.

21783609371738 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4068663376.

The product of its (nonzero) digits is 64012032, while the sum is 65.

The spelling of 21783609371738 in words is "twenty-one trillion, seven hundred eighty-three billion, six hundred nine million, three hundred seventy-one thousand, seven hundred thirty-eight".