1421597665 has 4 divisors (see below), whose sum is σ = 1705917204. Its totient is φ = 1137278128.

The previous prime is 1421597629. The next prime is 1421597707. The reversal of 1421597665 is 5667951241.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5667951241 = 163 ⋅34772707.

It can be written as a sum of positive squares in 2 ways, for example, as 183683809 + 1237913856 = 13553^2 + 35184^2 .

It is a cyclic number.

It is not a de Polignac number, because 1421597665 - 2¹⁵ = 1421564897 is a prime.

It is a super-2 number, since 2×1421597665² = 4041879842266904450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 142159762 + ... + 142159771.

It is an arithmetic number, because the mean of its divisors is an integer number (426479301).

Almost surely, 2^1421597665 is an apocalyptic number.

It is an amenable number.

1421597665 is a deficient number, since it is larger than the sum of its proper divisors (284319539).

1421597665 is an equidigital number, since it uses as much as digits as its factorization.

1421597665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 284319538.

The product of its digits is 453600, while the sum is 46.

The square root of 1421597665 is about 37704.0802168678. The cubic root of 1421597665 is about 1124.4122467282.

The spelling of 1421597665 in words is "one billion, four hundred twenty-one million, five hundred ninety-seven thousand, six hundred sixty-five".