2561535401 has 8 divisors (see below), whose sum is σ = 2713092264. Its totient is φ = 2410076160.

The previous prime is 2561535397. The next prime is 2561535409. The reversal of 2561535401 is 1045351652.

It can be written as a sum of positive squares in 4 ways, for example, as 513067801 + 2048467600 = 22651^2 + 45260^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2561535401 - 2² = 2561535397 is a prime.

It is a super-2 number, since 2×2561535401² = 13122927221152461602, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (2561535409) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33581 + ... + 79061.

It is an arithmetic number, because the mean of its divisors is an integer number (339136533).

Almost surely, 2^2561535401 is an apocalyptic number.

It is an amenable number.

2561535401 is a deficient number, since it is larger than the sum of its proper divisors (151556863).

2561535401 is a wasteful number, since it uses less digits than its factorization.

2561535401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48811.

The product of its (nonzero) digits is 18000, while the sum is 32.

The square root of 2561535401 is about 50611.6133016919. The cubic root of 2561535401 is about 1368.2541921391.

It can be divided in two parts, 25615 and 35401, that added together give a palindrome (61016).

The spelling of 2561535401 in words is "two billion, five hundred sixty-one million, five hundred thirty-five thousand, four hundred one".