21538175722 has 32 divisors (see below), whose sum is σ = 38832804864. Its totient is φ = 8764329600.

The previous prime is 21538175671. The next prime is 21538175723. The reversal of 21538175722 is 22757183512.

It is a super-4 number, since 4×21538175722⁴ (a number of 42 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (21538175723) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 445179 + ... + 491182.

It is an arithmetic number, because the mean of its divisors is an integer number (1213525152).

Almost surely, 2^21538175722 is an apocalyptic number.

21538175722 is a deficient number, since it is larger than the sum of its proper divisors (17294629142).

21538175722 is a wasteful number, since it uses less digits than its factorization.

21538175722 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936454.

The product of its digits is 235200, while the sum is 43.

The spelling of 21538175722 in words is "twenty-one billion, five hundred thirty-eight million, one hundred seventy-five thousand, seven hundred twenty-two".