1662511601 has 4 divisors (see below), whose sum is σ = 1662593652. Its totient is φ = 1662429552.

The previous prime is 1662511573. The next prime is 1662511603. The reversal of 1662511601 is 1061152661.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1061152661 = 31 ⋅34230731.

It can be written as a sum of positive squares in 2 ways, for example, as 311875600 + 1350636001 = 17660^2 + 36751^2 .

It is a cyclic number.

It is not a de Polignac number, because 1662511601 - 2¹⁴ = 1662495217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1662511603) 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, 13715 + ... + 59271.

It is an arithmetic number, because the mean of its divisors is an integer number (415648413).

Almost surely, 2^1662511601 is an apocalyptic number.

It is an amenable number.

1662511601 is a deficient number, since it is larger than the sum of its proper divisors (82051).

1662511601 is an equidigital number, since it uses as much as digits as its factorization.

1662511601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82050.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 1662511601 is about 40773.9083360916. The cubic root of 1662511601 is about 1184.6450065677.

The spelling of 1662511601 in words is "one billion, six hundred sixty-two million, five hundred eleven thousand, six hundred one".