21153601606 has 4 divisors (see below), whose sum is σ = 31730402412. Its totient is φ = 10576800802.

The previous prime is 21153601597. The next prime is 21153601633. The reversal of 21153601606 is 60610635112.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5288400400 + ... + 5288400403.

It is an arithmetic number, because the mean of its divisors is an integer number (7932600603).

Almost surely, 2^21153601606 is an apocalyptic number.

21153601606 is a deficient number, since it is larger than the sum of its proper divisors (10576800806).

21153601606 is a wasteful number, since it uses less digits than its factorization.

21153601606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10576800805.

The product of its (nonzero) digits is 6480, while the sum is 31.

The spelling of 21153601606 in words is "twenty-one billion, one hundred fifty-three million, six hundred one thousand, six hundred six".