261554034434450 has 12 divisors (see below), whose sum is σ = 486490504048170. Its totient is φ = 104621613773760.

The previous prime is 261554034434383. The next prime is 261554034434453. The reversal of 261554034434450 is 54434430455162.

It can be written as a sum of positive squares in 3 ways, for example, as 117690538069729 + 143863496364721 = 10848527^2 + 11994311^2 .

It is a Harshad number since it is a multiple of its sum of digits (50), and also a Moran number because the ratio is a prime number: 5231080688689 = 261554034434450 / (2 + 6 + 1 + 5 + 5 + 4 + 0 + 3 + 4 + 4 + 3 + 4 + 4 + 5 + 0).

It is not an unprimeable number, because it can be changed into a prime (261554034434453) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2615540344295 + ... + 2615540344394.

Almost surely, 2^{261554034434450} is an apocalyptic number.

261554034434450 is a deficient number, since it is larger than the sum of its proper divisors (224936469613720).

261554034434450 is a wasteful number, since it uses less digits than its factorization.

261554034434450 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5231080688701 (or 5231080688696 counting only the distinct ones).

The product of its (nonzero) digits is 13824000, while the sum is 50.

The spelling of 261554034434450 in words is "two hundred sixty-one trillion, five hundred fifty-four billion, thirty-four million, four hundred thirty-four thousand, four hundred fifty".