261573400001 has 4 divisors (see below), whose sum is σ = 264724886832. Its totient is φ = 258421913172.

The previous prime is 261573399991. The next prime is 261573400087. The reversal of 261573400001 is 100004375162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261573400001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261573400201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1575743291 + ... + 1575743456.

It is an arithmetic number, because the mean of its divisors is an integer number (66181221708).

Almost surely, 2^261573400001 is an apocalyptic number.

It is an amenable number.

261573400001 is a deficient number, since it is larger than the sum of its proper divisors (3151486831).

261573400001 is an equidigital number, since it uses as much as digits as its factorization.

261573400001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3151486830.

The product of its (nonzero) digits is 5040, while the sum is 29.

Adding to 261573400001 its reverse (100004375162), we get a palindrome (361577775163).

The spelling of 261573400001 in words is "two hundred sixty-one billion, five hundred seventy-three million, four hundred thousand, one".