1201503661 has 4 divisors (see below), whose sum is σ = 1202414524. Its totient is φ = 1200592800.

The previous prime is 1201503599. The next prime is 1201503757. The reversal of 1201503661 is 1663051021.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 887682436 + 313821225 = 29794^2 + 17715^2 .

It is a cyclic number.

It is not a de Polignac number, because 1201503661 - 2⁷ = 1201503533 is a prime.

It is a super-2 number, since 2×1201503661² = 2887222094792805842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1201503761) 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, 453450 + ... + 456091.

It is an arithmetic number, because the mean of its divisors is an integer number (300603631).

Almost surely, 2^1201503661 is an apocalyptic number.

It is an amenable number.

1201503661 is a deficient number, since it is larger than the sum of its proper divisors (910863).

1201503661 is an equidigital number, since it uses as much as digits as its factorization.

1201503661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910862.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 1201503661 is about 34662.7128338219. The cubic root of 1201503661 is about 1063.1022389891.

Adding to 1201503661 its reverse (1663051021), we get a palindrome (2864554682).

The spelling of 1201503661 in words is "one billion, two hundred one million, five hundred three thousand, six hundred sixty-one".