1625427198721 has 4 divisors (see below), whose sum is σ = 1681476412500. Its totient is φ = 1569377984944.

The previous prime is 1625427198719. The next prime is 1625427198749. The reversal of 1625427198721 is 1278917245261.

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 697934930625 + 927492268096 = 835425^2 + 963064^2 .

It is a cyclic number.

It is not a de Polignac number, because 1625427198721 - 2¹ = 1625427198719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1625427190721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28024606846 + ... + 28024606903.

It is an arithmetic number, because the mean of its divisors is an integer number (420369103125).

Almost surely, 2^{1625427198721} is an apocalyptic number.

It is an amenable number.

1625427198721 is a deficient number, since it is larger than the sum of its proper divisors (56049213779).

1625427198721 is an equidigital number, since it uses as much as digits as its factorization.

1625427198721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56049213778.

The product of its digits is 3386880, while the sum is 55.

The spelling of 1625427198721 in words is "one trillion, six hundred twenty-five billion, four hundred twenty-seven million, one hundred ninety-eight thousand, seven hundred twenty-one".