21123573706 has 8 divisors (see below), whose sum is σ = 31685977440. Its totient is φ = 10561581228.

The previous prime is 21123573637. The next prime is 21123573719. The reversal of 21123573706 is 60737532112.

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

It is a super-2 number, since 2×21123573706² (a number of 21 digits) contains 22 as substring.

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, 146835 + ... + 252601.

It is an arithmetic number, because the mean of its divisors is an integer number (3960747180).

Almost surely, 2^21123573706 is an apocalyptic number.

21123573706 is a deficient number, since it is larger than the sum of its proper divisors (10562403734).

21123573706 is a wasteful number, since it uses less digits than its factorization.

21123573706 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205628.

The product of its (nonzero) digits is 52920, while the sum is 37.

The spelling of 21123573706 in words is "twenty-one billion, one hundred twenty-three million, five hundred seventy-three thousand, seven hundred six".