21312305201 has 4 divisors (see below), whose sum is σ = 23249787504. Its totient is φ = 19374822900.

The previous prime is 21312305107. The next prime is 21312305237. The reversal of 21312305201 is 10250321312.

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 not a de Polignac number, because 21312305201 - 2²² = 21308110897 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21312305801) 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, 968741135 + ... + 968741156.

It is an arithmetic number, because the mean of its divisors is an integer number (5812446876).

Almost surely, 2^21312305201 is an apocalyptic number.

It is an amenable number.

21312305201 is a deficient number, since it is larger than the sum of its proper divisors (1937482303).

21312305201 is a wasteful number, since it uses less digits than its factorization.

21312305201 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1937482302.

The product of its (nonzero) digits is 360, while the sum is 20.

Adding to 21312305201 its reverse (10250321312), we get a palindrome (31562626513).

The spelling of 21312305201 in words is "twenty-one billion, three hundred twelve million, three hundred five thousand, two hundred one".