21000015707 has 8 divisors (see below), whose sum is σ = 22910513472. Its totient is φ = 19089752200.

The previous prime is 21000015689. The next prime is 21000015709. The reversal of 21000015707 is 70751000012.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21000015707 - 2⁶ = 21000015643 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21000015709) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166508 + ... + 264054.

It is an arithmetic number, because the mean of its divisors is an integer number (2863814184).

Almost surely, 2^21000015707 is an apocalyptic number.

21000015707 is a deficient number, since it is larger than the sum of its proper divisors (1910497765).

21000015707 is a wasteful number, since it uses less digits than its factorization.

21000015707 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 117129.

The product of its (nonzero) digits is 490, while the sum is 23.

Adding to 21000015707 its reverse (70751000012), we get a palindrome (91751015719).

The spelling of 21000015707 in words is "twenty-one billion, fifteen thousand, seven hundred seven".