261007990 has 16 divisors (see below), whose sum is σ = 482512752. Its totient is φ = 101581344.

The previous prime is 261007969. The next prime is 261007991. The reversal of 261007990 is 99700162.

261007990 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261007991) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 352344 + ... + 353083.

It is an arithmetic number, because the mean of its divisors is an integer number (30157047).

Almost surely, 2^261007990 is an apocalyptic number.

261007990 is a deficient number, since it is larger than the sum of its proper divisors (221504762).

261007990 is a wasteful number, since it uses less digits than its factorization.

261007990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705471.

The product of its (nonzero) digits is 6804, while the sum is 34.

The square root of 261007990 is about 16155.7417038030. The cubic root of 261007990 is about 639.0741740385.

It can be divided in two parts, 26 and 1007990, that added together give a square (1008016 = 1004²).

The spelling of 261007990 in words is "two hundred sixty-one million, seven thousand, nine hundred ninety".