261630007901 has 4 divisors (see below), whose sum is σ = 261680608704. Its totient is φ = 261579407100.

The previous prime is 261630007889. The next prime is 261630007907. The reversal of 261630007901 is 109700036162.

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 not a de Polignac number, because 261630007901 - 2³⁴ = 244450138717 is a prime.

It is a super-2 number, since 2×261630007901² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261630007907) 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, 25292645 + ... + 25302986.

It is an arithmetic number, because the mean of its divisors is an integer number (65420152176).

Almost surely, 2^261630007901 is an apocalyptic number.

It is an amenable number.

261630007901 is a deficient number, since it is larger than the sum of its proper divisors (50600803).

261630007901 is an equidigital number, since it uses as much as digits as its factorization.

261630007901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50600802.

The product of its (nonzero) digits is 13608, while the sum is 35.

The spelling of 261630007901 in words is "two hundred sixty-one billion, six hundred thirty million, seven thousand, nine hundred one".