661101403 has 4 divisors (see below), whose sum is σ = 663674040. Its totient is φ = 658528768.

The previous prime is 661101401. The next prime is 661101439. The reversal of 661101403 is 304101166.

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: 304101166 = 2 ⋅152050583.

It is a cyclic number.

It is not a de Polignac number, because 661101403 - 2¹ = 661101401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661101401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1285933 + ... + 1286446.

It is an arithmetic number, because the mean of its divisors is an integer number (165918510).

Almost surely, 2^661101403 is an apocalyptic number.

661101403 is a deficient number, since it is larger than the sum of its proper divisors (2572637).

661101403 is a wasteful number, since it uses less digits than its factorization.

661101403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2572636.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 661101403 is about 25711.8922485297. The cubic root of 661101403 is about 871.1428162118.

Adding to 661101403 its reverse (304101166), we get a palindrome (965202569).

The spelling of 661101403 in words is "six hundred sixty-one million, one hundred one thousand, four hundred three".