261301520661602 has 8 divisors (see below), whose sum is σ = 391952416183596. Its totient is φ = 130650715267072.

The previous prime is 261301520661529. The next prime is 261301520661613. The reversal of 261301520661602 is 206166025103162.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 156240025159201 + 105061495502401 = 12499601^2 + 10249951^2 .

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

It is a super-4 number, since 4×261301520661602⁴ (a number of 59 digits) contains 4444 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 261301520661602.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14745623 + ... + 27203610.

Almost surely, 2^{261301520661602} is an apocalyptic number.

261301520661602 is a deficient number, since it is larger than the sum of its proper divisors (130650895521994).

261301520661602 is a wasteful number, since it uses less digits than its factorization.

261301520661602 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45063732.

The product of its (nonzero) digits is 155520, while the sum is 41.

Adding to 261301520661602 its reverse (206166025103162), we get a palindrome (467467545764764).

The spelling of 261301520661602 in words is "two hundred sixty-one trillion, three hundred one billion, five hundred twenty million, six hundred sixty-one thousand, six hundred two".