73578661 has 4 divisors (see below), whose sum is σ = 79238572. Its totient is φ = 67918752.

The previous prime is 73578653. The next prime is 73578709. The reversal of 73578661 is 16687537.

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

It can be written as a sum of positive squares in 2 ways, for example, as 50481025 + 23097636 = 7105^2 + 4806^2 .

It is a cyclic number.

It is not a de Polignac number, because 73578661 - 2³ = 73578653 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 (73578761) 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, 2829936 + ... + 2829961.

It is an arithmetic number, because the mean of its divisors is an integer number (19809643).

Almost surely, 2^73578661 is an apocalyptic number.

It is an amenable number.

73578661 is a deficient number, since it is larger than the sum of its proper divisors (5659911).

73578661 is a wasteful number, since it uses less digits than its factorization.

73578661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5659910.

The product of its digits is 211680, while the sum is 43.

The square root of 73578661 is about 8577.8004756464. The cubic root of 73578661 is about 419.0353161811.

The spelling of 73578661 in words is "seventy-three million, five hundred seventy-eight thousand, six hundred sixty-one".