1545361661 has 4 divisors (see below), whose sum is σ = 1545675552. Its totient is φ = 1545047772.

The previous prime is 1545361621. The next prime is 1545361663. The reversal of 1545361661 is 1661635451.

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: 1661635451 = 7 ⋅237376493.

It is a cyclic number.

It is not a de Polignac number, because 1545361661 - 2¹⁰ = 1545360637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1545361663) 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, 149441 + ... + 159446.

It is an arithmetic number, because the mean of its divisors is an integer number (386418888).

Almost surely, 2^1545361661 is an apocalyptic number.

It is an amenable number.

1545361661 is a deficient number, since it is larger than the sum of its proper divisors (313891).

1545361661 is an equidigital number, since it uses as much as digits as its factorization.

1545361661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 313890.

The product of its digits is 64800, while the sum is 38.

The square root of 1545361661 is about 39311.0882703595. The cubic root of 1545361661 is about 1156.1389815161.

The spelling of 1545361661 in words is "one billion, five hundred forty-five million, three hundred sixty-one thousand, six hundred sixty-one".