1261149120 has 672 divisors, whose sum is σ = 5568915456. Its totient is φ = 256481280.

The previous prime is 1261149101. The next prime is 1261149137. The reversal of 1261149120 is 219411621.

1261149120 is a `hidden beast` number, since 1 + 2 + 611 + 49 + 1 + 2 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (672).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 26832937 + ... + 26832983.

Almost surely, 2^1261149120 is an apocalyptic number.

1261149120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1261149120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2784457728).

1261149120 is an abundant number, since it is smaller than the sum of its proper divisors (4307766336).

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

1261149120 is a wasteful number, since it uses less digits than its factorization.

1261149120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110 (or 75 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 1261149120 is about 35512.6614040683. The cubic root of 1261149120 is about 1080.4105435076.

The spelling of 1261149120 in words is "one billion, two hundred sixty-one million, one hundred forty-nine thousand, one hundred twenty".