261853946 has 4 divisors (see below), whose sum is σ = 392780922. Its totient is φ = 130926972.

The previous prime is 261853939. The next prime is 261853979. The reversal of 261853946 is 649358162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 649358162 = 2 ⋅324679081.

It can be written as a sum of positive squares in only one way, i.e., 166693921 + 95160025 = 12911^2 + 9755^2 .

It is a junction number, because it is equal to n+sod(n) for n = 261853897 and 261853906.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65463485 + ... + 65463488.

Almost surely, 2^261853946 is an apocalyptic number.

261853946 is a deficient number, since it is larger than the sum of its proper divisors (130926976).

261853946 is a wasteful number, since it uses less digits than its factorization.

261853946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 130926975.

The product of its digits is 311040, while the sum is 44.

The square root of 261853946 is about 16181.9018041762. The cubic root of 261853946 is about 639.7638663376.

The spelling of 261853946 in words is "two hundred sixty-one million, eight hundred fifty-three thousand, nine hundred forty-six".