261250000 has 160 divisors (see below), whose sum is σ = 726560640. Its totient is φ = 90000000.

The previous prime is 261249973. The next prime is 261250027. The reversal of 261250000 is 52162.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (261249973) and next prime (261250027).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13749991 + ... + 13750009.

It is an arithmetic number, because the mean of its divisors is an integer number (4541004).

Almost surely, 2^261250000 is an apocalyptic number.

261250000 is a gapful number since it is divisible by the number (20) 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 261250000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363280320).

261250000 is an abundant number, since it is smaller than the sum of its proper divisors (465310640).

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

261250000 is an frugal number, since it uses more digits than its factorization.

261250000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73 (or 37 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 261250000 is about 16163.2298752446. The cubic root of 261250000 is about 639.2716323153.

The spelling of 261250000 in words is "two hundred sixty-one million, two hundred fifty thousand".