21254545201 has 4 divisors (see below), whose sum is σ = 21256980004. Its totient is φ = 21252110400.

The previous prime is 21254545199. The next prime is 21254545217. The reversal of 21254545201 is 10254545212.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8121614400 + 13132930801 = 90120^2 + 114599^2 .

It is a cyclic number.

It is not a de Polignac number, because 21254545201 - 2¹ = 21254545199 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21254545261) 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, 1204260 + ... + 1221781.

It is an arithmetic number, because the mean of its divisors is an integer number (5314245001).

Almost surely, 2^21254545201 is an apocalyptic number.

It is an amenable number.

21254545201 is a deficient number, since it is larger than the sum of its proper divisors (2434803).

21254545201 is an equidigital number, since it uses as much as digits as its factorization.

21254545201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2434802.

The product of its (nonzero) digits is 16000, while the sum is 31.

The spelling of 21254545201 in words is "twenty-one billion, two hundred fifty-four million, five hundred forty-five thousand, two hundred one".