261323551658 has 32 divisors (see below), whose sum is σ = 427627468800. Its totient is φ = 119045209536.

The previous prime is 261323551651. The next prime is 261323551667. The reversal of 261323551658 is 856155323162.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (261323551651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2250263 + ... + 2363541.

It is an arithmetic number, because the mean of its divisors is an integer number (13363358400).

Almost surely, 2^261323551658 is an apocalyptic number.

261323551658 is a deficient number, since it is larger than the sum of its proper divisors (166303917142).

261323551658 is a wasteful number, since it uses less digits than its factorization.

261323551658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 114446.

The product of its digits is 1296000, while the sum is 47.

The spelling of 261323551658 in words is "two hundred sixty-one billion, three hundred twenty-three million, five hundred fifty-one thousand, six hundred fifty-eight".