661545413351 has 4 divisors (see below), whose sum is σ = 662903823312. Its totient is φ = 660187003392.

The previous prime is 661545413327. The next prime is 661545413359. The reversal of 661545413351 is 153314545166.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 661545413351 - 2¹⁰ = 661545412327 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 (661545413359) 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, 679204250 + ... + 679205223.

It is an arithmetic number, because the mean of its divisors is an integer number (165725955828).

Almost surely, 2^661545413351 is an apocalyptic number.

661545413351 is a deficient number, since it is larger than the sum of its proper divisors (1358409961).

661545413351 is a wasteful number, since it uses less digits than its factorization.

661545413351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1358409960.

The product of its digits is 648000, while the sum is 44.

The spelling of 661545413351 in words is "six hundred sixty-one billion, five hundred forty-five million, four hundred thirteen thousand, three hundred fifty-one".