261099648 has 48 divisors (see below), whose sum is σ = 751344750. Its totient is φ = 87032832.

The previous prime is 261099599. The next prime is 261099649. The reversal of 261099648 is 846990162.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 148060224 + 113039424 = 12168^2 + 10632^2 .

It is a tau number, because it is divible by the number of its divisors (48).

It is not an unprimeable number, because it can be changed into a prime (261099649) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 112173 + ... + 114476.

Almost surely, 2^261099648 is an apocalyptic number.

It is an amenable number.

261099648 is an abundant number, since it is smaller than the sum of its proper divisors (490245102).

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

261099648 is a wasteful number, since it uses less digits than its factorization.

261099648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 226669 (or 226654 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 261099648 is about 16158.5781552710. The cubic root of 261099648 is about 639.1489730325.

The spelling of 261099648 in words is "two hundred sixty-one million, ninety-nine thousand, six hundred forty-eight".