21783278001 has 8 divisors (see below), whose sum is σ = 29045311360. Its totient is φ = 14521714992.

The previous prime is 21783277951. The next prime is 21783278009. The reversal of 21783278001 is 10087238712.

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

It is not a de Polignac number, because 21783278001 - 2¹⁵ = 21783245233 is a prime.

It is a super-2 number, since 2×21783278001² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21783278009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10371 + ... + 208983.

It is an arithmetic number, because the mean of its divisors is an integer number (3630663920).

Almost surely, 2^21783278001 is an apocalyptic number.

It is an amenable number.

21783278001 is a deficient number, since it is larger than the sum of its proper divisors (7262033359).

21783278001 is a wasteful number, since it uses less digits than its factorization.

21783278001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 235175.

The product of its (nonzero) digits is 37632, while the sum is 39.

The spelling of 21783278001 in words is "twenty-one billion, seven hundred eighty-three million, two hundred seventy-eight thousand, one".