15745434821 has 2 divisors, whose sum is σ = 15745434822. Its totient is φ = 15745434820.

The previous prime is 15745434811. The next prime is 15745434869. The reversal of 15745434821 is 12843454751.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14498568100 + 1246866721 = 120410^2 + 35311^2 .

It is an emirp because it is prime and its reverse (12843454751) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15745434821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15745434811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7872717410 + 7872717411.

It is an arithmetic number, because the mean of its divisors is an integer number (7872717411).

Almost surely, 2^15745434821 is an apocalyptic number.

It is an amenable number.

15745434821 is a deficient number, since it is larger than the sum of its proper divisors (1).

15745434821 is an equidigital number, since it uses as much as digits as its factorization.

15745434821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 537600, while the sum is 44.

The spelling of 15745434821 in words is "fifteen billion, seven hundred forty-five million, four hundred thirty-four thousand, eight hundred twenty-one".