1261666315 has 32 divisors (see below), whose sum is σ = 1927658880. Its totient is φ = 771047424.

The previous prime is 1261666313. The next prime is 1261666321. The reversal of 1261666315 is 5136661621.

It is not a de Polignac number, because 1261666315 - 2¹ = 1261666313 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1261666313) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 34614 + ... + 61003.

It is an arithmetic number, because the mean of its divisors is an integer number (60239340).

Almost surely, 2^1261666315 is an apocalyptic number.

1261666315 is a deficient number, since it is larger than the sum of its proper divisors (665992565).

1261666315 is a wasteful number, since it uses less digits than its factorization.

1261666315 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95671.

The product of its digits is 38880, while the sum is 37.

The square root of 1261666315 is about 35519.9424971381. The cubic root of 1261666315 is about 1080.5582148005.

The spelling of 1261666315 in words is "one billion, two hundred sixty-one million, six hundred sixty-six thousand, three hundred fifteen".