261661354 has 16 divisors (see below), whose sum is σ = 395577000. Its totient is φ = 129806784.

The previous prime is 261661349. The next prime is 261661357. The reversal of 261661354 is 453166162.

261661354 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 236390625 + 25270729 = 15375^2 + 5027^2 .

It is a super-2 number, since 2×261661354² = 136933328354226632, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261661357) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 159024 + ... + 160660.

Almost surely, 2^261661354 is an apocalyptic number.

261661354 is a deficient number, since it is larger than the sum of its proper divisors (133915646).

261661354 is a wasteful number, since it uses less digits than its factorization.

261661354 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2217.

The product of its digits is 25920, while the sum is 34.

The square root of 261661354 is about 16175.9498639183. The cubic root of 261661354 is about 639.6069803784.

The spelling of 261661354 in words is "two hundred sixty-one million, six hundred sixty-one thousand, three hundred fifty-four".