261619090 has 16 divisors (see below), whose sum is σ = 472343040. Its totient is φ = 104330160.

The previous prime is 261619087. The next prime is 261619091. The reversal of 261619090 is 90916162.

It is not an unprimeable number, because it can be changed into a prime (261619091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 36210 + ... + 42829.

It is an arithmetic number, because the mean of its divisors is an integer number (29521440).

Almost surely, 2^261619090 is an apocalyptic number.

261619090 is a deficient number, since it is larger than the sum of its proper divisors (210723950).

261619090 is a wasteful number, since it uses less digits than its factorization.

261619090 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79377.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 261619090 is about 16174.6434272908. The cubic root of 261619090 is about 639.5725417111.

The spelling of 261619090 in words is "two hundred sixty-one million, six hundred nineteen thousand, ninety".