1261630145 has 8 divisors (see below), whose sum is σ = 1514153256. Its totient is φ = 1009172736.

The previous prime is 1261630103. The next prime is 1261630159. The reversal of 1261630145 is 5410361621.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 431268289 + 830361856 = 20767^2 + 28816^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1261630145 - 2¹⁴ = 1261613761 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50969 + ... + 71561.

It is an arithmetic number, because the mean of its divisors is an integer number (189269157).

Almost surely, 2^1261630145 is an apocalyptic number.

It is an amenable number.

1261630145 is a deficient number, since it is larger than the sum of its proper divisors (252523111).

1261630145 is a wasteful number, since it uses less digits than its factorization.

1261630145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32851.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 1261630145 is about 35519.4333428899. The cubic root of 1261630145 is about 1080.5478887305.

Adding to 1261630145 its reverse (5410361621), we get a palindrome (6671991766).

The spelling of 1261630145 in words is "one billion, two hundred sixty-one million, six hundred thirty thousand, one hundred forty-five".