1261911612 has 48 divisors (see below), whose sum is σ = 3248314272. Its totient is φ = 378808320.

The previous prime is 1261911589. The next prime is 1261911631. The reversal of 1261911612 is 2161191621.

It is a super-3 number, since 3×1261911612³ (a number of 28 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1261911612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92253 + ... + 105044.

It is an arithmetic number, because the mean of its divisors is an integer number (67673214).

Almost surely, 2^1261911612 is an apocalyptic number.

1261911612 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1261911612 is an abundant number, since it is smaller than the sum of its proper divisors (1986402660).

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

1261911612 is a wasteful number, since it uses less digits than its factorization.

1261911612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197358 (or 197356 counting only the distinct ones).

The product of its digits is 1296, while the sum is 30.

The square root of 1261911612 is about 35523.3952769157. The cubic root of 1261911612 is about 1080.6282387335.

The spelling of 1261911612 in words is "one billion, two hundred sixty-one million, nine hundred eleven thousand, six hundred twelve".