661563465 has 16 divisors (see below), whose sum is σ = 1065515136. Its totient is φ = 350496000.

The previous prime is 661563431. The next prime is 661563491. The reversal of 661563465 is 564365166.

661563465 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 661563465 - 2¹⁷ = 661432393 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 143776 + ... + 148305.

It is an arithmetic number, because the mean of its divisors is an integer number (66594696).

Almost surely, 2^661563465 is an apocalyptic number.

It is an amenable number.

661563465 is a deficient number, since it is larger than the sum of its proper divisors (403951671).

661563465 is a wasteful number, since it uses less digits than its factorization.

661563465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292240.

The product of its digits is 388800, while the sum is 42.

The square root of 661563465 is about 25720.8760542871. The cubic root of 661563465 is about 871.3457241916.

The spelling of 661563465 in words is "six hundred sixty-one million, five hundred sixty-three thousand, four hundred sixty-five".