1261671090 has 16 divisors (see below), whose sum is σ = 3028010688. Its totient is φ = 336445616.

The previous prime is 1261671053. The next prime is 1261671091. The reversal of 1261671090 is 901761621.

It is not an unprimeable number, because it can be changed into a prime (1261671091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21027822 + ... + 21027881.

It is an arithmetic number, because the mean of its divisors is an integer number (189250668).

Almost surely, 2^1261671090 is an apocalyptic number.

1261671090 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1261671090 is an abundant number, since it is smaller than the sum of its proper divisors (1766339598).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1261671090 is a wasteful number, since it uses less digits than its factorization.

1261671090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42055713.

The product of its (nonzero) digits is 4536, while the sum is 33.

The square root of 1261671090 is about 35520.0097128365. The cubic root of 1261671090 is about 1080.5595779869.

The spelling of 1261671090 in words is "one billion, two hundred sixty-one million, six hundred seventy-one thousand, ninety".