21006065015 has 8 divisors (see below), whose sum is σ = 27146299488. Its totient is φ = 15512171040.

The previous prime is 21006064949. The next prime is 21006065021. The reversal of 21006065015 is 51056060012.

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

It is not a de Polignac number, because 21006065015 - 2¹² = 21006060919 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 161585051 + ... + 161585180.

It is an arithmetic number, because the mean of its divisors is an integer number (3393287436).

Almost surely, 2^21006065015 is an apocalyptic number.

21006065015 is a deficient number, since it is larger than the sum of its proper divisors (6140234473).

21006065015 is a wasteful number, since it uses less digits than its factorization.

21006065015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323170249.

The product of its (nonzero) digits is 1800, while the sum is 26.

The spelling of 21006065015 in words is "twenty-one billion, six million, sixty-five thousand, fifteen".