661480811 has 4 divisors (see below), whose sum is σ = 663254592. Its totient is φ = 659707032.

The previous prime is 661480777. The next prime is 661480819. The reversal of 661480811 is 118084166.

It is a happy number.

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 661480811 - 2¹⁰ = 661479787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661480819) 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, 886331 + ... + 887076.

It is an arithmetic number, because the mean of its divisors is an integer number (165813648).

Almost surely, 2^661480811 is an apocalyptic number.

661480811 is a deficient number, since it is larger than the sum of its proper divisors (1773781).

661480811 is a wasteful number, since it uses less digits than its factorization.

661480811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1773780.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 661480811 is about 25719.2692547825. The cubic root of 661480811 is about 871.3094347989.

The spelling of 661480811 in words is "six hundred sixty-one million, four hundred eighty thousand, eight hundred eleven".