21407001745 has 4 divisors (see below), whose sum is σ = 25688402100. Its totient is φ = 17125601392.

The previous prime is 21407001743. The next prime is 21407001769. The reversal of 21407001745 is 54710070412.

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 12190809744 + 9216192001 = 110412^2 + 96001^2 .

It is a cyclic number.

It is not a de Polignac number, because 21407001745 - 2¹ = 21407001743 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21407001743) 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, 2140700170 + ... + 2140700179.

It is an arithmetic number, because the mean of its divisors is an integer number (6422100525).

Almost surely, 2^21407001745 is an apocalyptic number.

It is an amenable number.

21407001745 is a deficient number, since it is larger than the sum of its proper divisors (4281400355).

21407001745 is an equidigital number, since it uses as much as digits as its factorization.

21407001745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4281400354.

The product of its (nonzero) digits is 7840, while the sum is 31.

The spelling of 21407001745 in words is "twenty-one billion, four hundred seven million, one thousand, seven hundred forty-five".