661237603 has 16 divisors (see below), whose sum is σ = 755677440. Its totient is φ = 573924384.

The previous prime is 661237597. The next prime is 661237609. The reversal of 661237603 is 306732166.

It is an interprime number because it is at equal distance from previous prime (661237597) and next prime (661237609).

It is a cyclic number.

It is not a de Polignac number, because 661237603 - 2¹⁷ = 661106531 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661237609) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1101 + ... + 36382.

It is an arithmetic number, because the mean of its divisors is an integer number (47229840).

Almost surely, 2^661237603 is an apocalyptic number.

661237603 is a deficient number, since it is larger than the sum of its proper divisors (94439837).

661237603 is a wasteful number, since it uses less digits than its factorization.

661237603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37578.

The product of its (nonzero) digits is 27216, while the sum is 34.

The square root of 661237603 is about 25714.5406919898. The cubic root of 661237603 is about 871.2026363361.

Adding to 661237603 its reverse (306732166), we get a palindrome (967969769).

The spelling of 661237603 in words is "six hundred sixty-one million, two hundred thirty-seven thousand, six hundred three".