661048291 has 4 divisors (see below), whose sum is σ = 665006832. Its totient is φ = 657089752.

The previous prime is 661048217. The next prime is 661048303. The reversal of 661048291 is 192840166.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 192840166 = 2 ⋅96420083.

It is a cyclic number.

It is not a de Polignac number, because 661048291 - 2¹⁷ = 660917219 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 661048291.

It is not an unprimeable number, because it can be changed into a prime (661048691) 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, 1979020 + ... + 1979353.

It is an arithmetic number, because the mean of its divisors is an integer number (166251708).

Almost surely, 2^661048291 is an apocalyptic number.

661048291 is a deficient number, since it is larger than the sum of its proper divisors (3958541).

661048291 is a wasteful number, since it uses less digits than its factorization.

661048291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3958540.

The product of its (nonzero) digits is 20736, while the sum is 37.

The square root of 661048291 is about 25710.8593983165. The cubic root of 661048291 is about 871.1194867719.

The spelling of 661048291 in words is "six hundred sixty-one million, forty-eight thousand, two hundred ninety-one".