261625506 has 32 divisors (see below), whose sum is σ = 551041920. Its totient is φ = 82646784.

The previous prime is 261625493. The next prime is 261625519. The reversal of 261625506 is 605526162.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (261625493) and next prime (261625519).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6346 + ... + 23738.

It is an arithmetic number, because the mean of its divisors is an integer number (17220060).

Almost surely, 2^261625506 is an apocalyptic number.

261625506 is an abundant number, since it is smaller than the sum of its proper divisors (289416414).

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

261625506 is a wasteful number, since it uses less digits than its factorization.

261625506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17530.

The product of its (nonzero) digits is 21600, while the sum is 33.

The square root of 261625506 is about 16174.8417612043. The cubic root of 261625506 is about 639.5777700042.

The spelling of 261625506 in words is "two hundred sixty-one million, six hundred twenty-five thousand, five hundred six".