1202311561 has 4 divisors (see below), whose sum is σ = 1311612624. Its totient is φ = 1093010500.

The previous prime is 1202311547. The next prime is 1202311567. The reversal of 1202311561 is 1651132021.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1202311561 - 2¹⁷ = 1202180489 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1202311567) 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, 54650515 + ... + 54650536.

It is an arithmetic number, because the mean of its divisors is an integer number (327903156).

Almost surely, 2^1202311561 is an apocalyptic number.

1202311561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1202311561 is a deficient number, since it is larger than the sum of its proper divisors (109301063).

1202311561 is a wasteful number, since it uses less digits than its factorization.

1202311561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109301062.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 1202311561 is about 34674.3646084539. The cubic root of 1202311561 is about 1063.3404648869.

Adding to 1202311561 its reverse (1651132021), we get a palindrome (2853443582).

The spelling of 1202311561 in words is "one billion, two hundred two million, three hundred eleven thousand, five hundred sixty-one".