1261666252 has 24 divisors (see below), whose sum is σ = 2752727040. Its totient is φ = 491558160.

The previous prime is 1261666247. The next prime is 1261666277. The reversal of 1261666252 is 2526661621.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2047852 + ... + 2048467.

It is an arithmetic number, because the mean of its divisors is an integer number (114696960).

Almost surely, 2^1261666252 is an apocalyptic number.

It is an amenable number.

1261666252 is an abundant number, since it is smaller than the sum of its proper divisors (1491060788).

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

1261666252 is a wasteful number, since it uses less digits than its factorization.

1261666252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4096341 (or 4096339 counting only the distinct ones).

The product of its digits is 51840, while the sum is 37.

The square root of 1261666252 is about 35519.9416103124. The cubic root of 1261666252 is about 1080.5581968150.

The spelling of 1261666252 in words is "one billion, two hundred sixty-one million, six hundred sixty-six thousand, two hundred fifty-two".