261889514 has 4 divisors (see below), whose sum is σ = 392834274. Its totient is φ = 130944756.

The previous prime is 261889513. The next prime is 261889541. The reversal of 261889514 is 415988162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 415988162 = 2 ⋅207994081.

It can be written as a sum of positive squares in only one way, i.e., 261889489 + 25 = 16183^2 + 5^2 .

It is a super-2 number, since 2×261889514² = 137172235086312392, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261889513) 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 as a sum of consecutive naturals, namely, 65472377 + ... + 65472380.

Almost surely, 2^261889514 is an apocalyptic number.

261889514 is a deficient number, since it is larger than the sum of its proper divisors (130944760).

261889514 is a wasteful number, since it uses less digits than its factorization.

261889514 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130944759.

The product of its digits is 138240, while the sum is 44.

The square root of 261889514 is about 16183.0007724155. Note that the first 3 decimals coincide. The cubic root of 261889514 is about 639.7928317098.

The spelling of 261889514 in words is "two hundred sixty-one million, eight hundred eighty-nine thousand, five hundred fourteen".