261245250 has 320 divisors, whose sum is σ = 887927040. Its totient is φ = 55987200.

The previous prime is 261245233. The next prime is 261245267. The reversal of 261245250 is 52542162.

261245250 is a `hidden beast` number, since 2 + 612 + 45 + 2 + 5 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (261245233) and next prime (261245267).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 2693202 + ... + 2693298.

It is an arithmetic number, because the mean of its divisors is an integer number (2774772).

Almost surely, 2^261245250 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261245250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (443963520).

261245250 is an abundant number, since it is smaller than the sum of its proper divisors (626681790).

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

261245250 is a wasteful number, since it uses less digits than its factorization.

261245250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152 (or 133 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

The square root of 261245250 is about 16163.0829361233. The cubic root of 261245250 is about 639.2677579183.

The spelling of 261245250 in words is "two hundred sixty-one million, two hundred forty-five thousand, two hundred fifty".