261439291007 has 4 divisors (see below), whose sum is σ = 261442889160. Its totient is φ = 261435692856.

The previous prime is 261439290997. The next prime is 261439291021. The reversal of 261439291007 is 700192934162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 700192934162 = 2 ⋅350096467081.

It is a cyclic number.

It is not a de Polignac number, because 261439291007 - 2¹⁴ = 261439274623 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261439291067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1687793 + ... + 1836170.

It is an arithmetic number, because the mean of its divisors is an integer number (65360722290).

Almost surely, 2^261439291007 is an apocalyptic number.

261439291007 is a deficient number, since it is larger than the sum of its proper divisors (3598153).

261439291007 is an equidigital number, since it uses as much as digits as its factorization.

261439291007 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3598152.

The product of its (nonzero) digits is 163296, while the sum is 44.

The spelling of 261439291007 in words is "two hundred sixty-one billion, four hundred thirty-nine million, two hundred ninety-one thousand, seven".