21202140401 has 4 divisors (see below), whose sum is σ = 22833074292. Its totient is φ = 19571206512.

The previous prime is 21202140397. The next prime is 21202140431. The reversal of 21202140401 is 10404120212.

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 2096266225 + 19105874176 = 45785^2 + 138224^2 .

It is not a de Polignac number, because 21202140401 - 2² = 21202140397 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21202140401.

It is not an unprimeable number, because it can be changed into a prime (21202140431) 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, 815466926 + ... + 815466951.

It is an arithmetic number, because the mean of its divisors is an integer number (5708268573).

Almost surely, 2^21202140401 is an apocalyptic number.

It is an amenable number.

21202140401 is a deficient number, since it is larger than the sum of its proper divisors (1630933891).

21202140401 is a wasteful number, since it uses less digits than its factorization.

21202140401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1630933890.

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 21202140401 its reverse (10404120212), we get a palindrome (31606260613).

The spelling of 21202140401 in words is "twenty-one billion, two hundred two million, one hundred forty thousand, four hundred one".