21001167813 has 8 divisors (see below), whose sum is σ = 28146643648. Its totient is φ = 13928235264.

The previous prime is 21001167809. The next prime is 21001167841. The reversal of 21001167813 is 31876110012.

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

It is not a de Polignac number, because 21001167813 - 2² = 21001167809 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21001167113) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 18135145 + ... + 18136302.

It is an arithmetic number, because the mean of its divisors is an integer number (3518330456).

Almost surely, 2^21001167813 is an apocalyptic number.

It is an amenable number.

21001167813 is a deficient number, since it is larger than the sum of its proper divisors (7145475835).

21001167813 is a wasteful number, since it uses less digits than its factorization.

21001167813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36271643.

The product of its (nonzero) digits is 2016, while the sum is 30.

Adding to 21001167813 its reverse (31876110012), we get a palindrome (52877277825).

The spelling of 21001167813 in words is "twenty-one billion, one million, one hundred sixty-seven thousand, eight hundred thirteen".