1261546650 has 432 divisors, whose sum is σ = 4430278944. Its totient is φ = 264539520.

The previous prime is 1261546639. The next prime is 1261546669. The reversal of 1261546650 is 566451621.

1261546650 is a `hidden beast` number, since 1 + 2 + 61 + 546 + 6 + 50 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 215 ways as a sum of consecutive naturals, for example, 7739469 + ... + 7739631.

Almost surely, 2^1261546650 is an apocalyptic number.

1261546650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261546650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2215139472).

1261546650 is an abundant number, since it is smaller than the sum of its proper divisors (3168732294).

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

1261546650 is a wasteful number, since it uses less digits than its factorization.

1261546650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217 (or 193 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 1261546650 is about 35518.2579809314. The cubic root of 1261546650 is about 1080.5240512277.

The spelling of 1261546650 in words is "one billion, two hundred sixty-one million, five hundred forty-six thousand, six hundred fifty".