21447770401 has 4 divisors (see below), whose sum is σ = 22709403972. Its totient is φ = 20186136832.

The previous prime is 21447770371. The next prime is 21447770413. The reversal of 21447770401 is 10407774412.

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 7047770401 + 14400000000 = 83951^2 + 120000^2 .

It is a cyclic number.

It is not a de Polignac number, because 21447770401 - 2¹³ = 21447762209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21447770431) 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, 630816760 + ... + 630816793.

It is an arithmetic number, because the mean of its divisors is an integer number (5677350993).

Almost surely, 2^21447770401 is an apocalyptic number.

It is an amenable number.

21447770401 is a deficient number, since it is larger than the sum of its proper divisors (1261633571).

21447770401 is a wasteful number, since it uses less digits than its factorization.

21447770401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1261633570.

The product of its (nonzero) digits is 43904, while the sum is 37.

The spelling of 21447770401 in words is "twenty-one billion, four hundred forty-seven million, seven hundred seventy thousand, four hundred one".