21021400213 has 4 divisors (see below), whose sum is σ = 22932436608. Its totient is φ = 19110363820.

The previous prime is 21021400193. The next prime is 21021400219. The reversal of 21021400213 is 31200412012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021400213 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 (21021400219) 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, 955518181 + ... + 955518202.

It is an arithmetic number, because the mean of its divisors is an integer number (5733109152).

Almost surely, 2^21021400213 is an apocalyptic number.

It is an amenable number.

21021400213 is a deficient number, since it is larger than the sum of its proper divisors (1911036395).

21021400213 is a wasteful number, since it uses less digits than its factorization.

21021400213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1911036394.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21021400213 its reverse (31200412012), we get a palindrome (52221812225).

The spelling of 21021400213 in words is "twenty-one billion, twenty-one million, four hundred thousand, two hundred thirteen".