261426637 has 4 divisors (see below), whose sum is σ = 261695196. Its totient is φ = 261158080.

The previous prime is 261426631. The next prime is 261426653. The reversal of 261426637 is 736624162.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 119006281 + 142420356 = 10909^2 + 11934^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261426637 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261426596 and 261426605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261426631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 132814 + ... + 134767.

It is an arithmetic number, because the mean of its divisors is an integer number (65423799).

Almost surely, 2^261426637 is an apocalyptic number.

It is an amenable number.

261426637 is a deficient number, since it is larger than the sum of its proper divisors (268559).

261426637 is an equidigital number, since it uses as much as digits as its factorization.

261426637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268558.

The product of its digits is 72576, while the sum is 37.

The square root of 261426637 is about 16168.6931135451. The cubic root of 261426637 is about 639.4156751655.

The spelling of 261426637 in words is "two hundred sixty-one million, four hundred twenty-six thousand, six hundred thirty-seven".