21642106005 has 24 divisors (see below), whose sum is σ = 40398598968. Its totient is φ = 10654574976.

The previous prime is 21642105937. The next prime is 21642106081. The reversal of 21642106005 is 50060124612.

21642106005 is a `hidden beast` number, since 2 + 1 + 6 + 42 + 10 + 600 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 459684 + 21641646321 = 678^2 + 147111^2 .

It is not a de Polignac number, because 21642106005 - 2²³ = 21633717397 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21642106005.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18496942 + ... + 18498111.

It is an arithmetic number, because the mean of its divisors is an integer number (1683274957).

Almost surely, 2^21642106005 is an apocalyptic number.

It is an amenable number.

21642106005 is a deficient number, since it is larger than the sum of its proper divisors (18756492963).

21642106005 is a wasteful number, since it uses less digits than its factorization.

21642106005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36995077 (or 36995074 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The spelling of 21642106005 in words is "twenty-one billion, six hundred forty-two million, one hundred six thousand, five".