1261025535 has 96 divisors (see below), whose sum is σ = 2695507200. Its totient is φ = 496419840.

The previous prime is 1261025509. The next prime is 1261025537. The reversal of 1261025535 is 5355201621.

It is a happy number.

It is not a de Polignac number, because 1261025535 - 2⁷ = 1261025407 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1261025537) by changing a digit.

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 95 ways as a sum of consecutive naturals, for example, 149511 + ... + 157719.

It is an arithmetic number, because the mean of its divisors is an integer number (28078200).

Almost surely, 2^1261025535 is an apocalyptic number.

1261025535 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

1261025535 is an abundant number, since it is smaller than the sum of its proper divisors (1434481665).

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

1261025535 is a wasteful number, since it uses less digits than its factorization.

1261025535 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8261 (or 8254 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 30.

The square root of 1261025535 is about 35510.9213482275. The cubic root of 1261025535 is about 1080.3752511179.

The spelling of 1261025535 in words is "one billion, two hundred sixty-one million, twenty-five thousand, five hundred thirty-five".