661632263 has 4 divisors (see below), whose sum is σ = 662051808. Its totient is φ = 661212720.

The previous prime is 661632241. The next prime is 661632311. The reversal of 661632263 is 362236166.

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 661632263 - 2⁶ = 661632199 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 (661632463) 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, 207398 + ... + 210563.

It is an arithmetic number, because the mean of its divisors is an integer number (165512952).

Almost surely, 2^661632263 is an apocalyptic number.

661632263 is a deficient number, since it is larger than the sum of its proper divisors (419545).

661632263 is a wasteful number, since it uses less digits than its factorization.

661632263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419544.

The product of its digits is 46656, while the sum is 35.

The square root of 661632263 is about 25722.2134156452. The cubic root of 661632263 is about 871.3759277767.

The spelling of 661632263 in words is "six hundred sixty-one million, six hundred thirty-two thousand, two hundred sixty-three".