21009628606 has 8 divisors (see below), whose sum is σ = 32283087984. Its totient is φ = 10248599280.

The previous prime is 21009628603. The next prime is 21009628609. The reversal of 21009628606 is 60682690012.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21009628603) and next prime (21009628609).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21009628603) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 128107410 + ... + 128107573.

It is an arithmetic number, because the mean of its divisors is an integer number (4035385998).

Almost surely, 2^21009628606 is an apocalyptic number.

21009628606 is a deficient number, since it is larger than the sum of its proper divisors (11273459378).

21009628606 is a wasteful number, since it uses less digits than its factorization.

21009628606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256215026.

The product of its (nonzero) digits is 62208, while the sum is 40.

The spelling of 21009628606 in words is "twenty-one billion, nine million, six hundred twenty-eight thousand, six hundred six".