1602065721 has 4 divisors (see below), whose sum is σ = 2136087632. Its totient is φ = 1068043812.

The previous prime is 1602065719. The next prime is 1602065723. The reversal of 1602065721 is 1275602061.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1275602061 = 3 ⋅425200687.

It is an interprime number because it is at equal distance from previous prime (1602065719) and next prime (1602065723).

It is not a de Polignac number, because 1602065721 - 2¹ = 1602065719 is a prime.

It is a super-2 number, since 2×1602065721² = 5133229148806499682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1602065723) 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, 267010951 + ... + 267010956.

It is an arithmetic number, because the mean of its divisors is an integer number (534021908).

Almost surely, 2^1602065721 is an apocalyptic number.

It is an amenable number.

1602065721 is a deficient number, since it is larger than the sum of its proper divisors (534021911).

1602065721 is an equidigital number, since it uses as much as digits as its factorization.

1602065721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534021910.

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 1602065721 is about 40025.8131834945. The cubic root of 1602065721 is about 1170.1102292231.

Adding to 1602065721 its reverse (1275602061), we get a palindrome (2877667782).

The spelling of 1602065721 in words is "one billion, six hundred two million, sixty-five thousand, seven hundred twenty-one".