21001200040005 has 32 divisors (see below), whose sum is σ = 35504930672640. Its totient is φ = 10570786102080.

The previous prime is 21001200039991. The next prime is 21001200040019. The reversal of 21001200040005 is 50004000210012.

It is an interprime number because it is at equal distance from previous prime (21001200039991) and next prime (21001200040019).

It is not a de Polignac number, because 21001200040005 - 2¹² = 21001200035909 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 140017101 + ... + 140167010.

It is an arithmetic number, because the mean of its divisors is an integer number (1109529083520).

Almost surely, 2^{21001200040005} is an apocalyptic number.

It is an amenable number.

21001200040005 is a deficient number, since it is larger than the sum of its proper divisors (14503730632635).

21001200040005 is a wasteful number, since it uses less digits than its factorization.

21001200040005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280184401.

The product of its (nonzero) digits is 80, while the sum is 15.

Adding to 21001200040005 its reverse (50004000210012), we get a palindrome (71005200250017).

The spelling of 21001200040005 in words is "twenty-one trillion, one billion, two hundred million, forty thousand, five".