21173740705 has 16 divisors (see below), whose sum is σ = 27370252224. Its totient is φ = 15631842240.

The previous prime is 21173740663. The next prime is 21173740747. The reversal of 21173740705 is 50704737112.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21173740663) and next prime (21173740747).

It is not a de Polignac number, because 21173740705 - 2¹⁵ = 21173707937 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 215290 + ... + 297820.

It is an arithmetic number, because the mean of its divisors is an integer number (1710640764).

Almost surely, 2^21173740705 is an apocalyptic number.

It is an amenable number.

21173740705 is a deficient number, since it is larger than the sum of its proper divisors (6196511519).

21173740705 is a wasteful number, since it uses less digits than its factorization.

21173740705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86496.

The product of its (nonzero) digits is 41160, while the sum is 37.

The spelling of 21173740705 in words is "twenty-one billion, one hundred seventy-three million, seven hundred forty thousand, seven hundred five".