261111447533 has 2 divisors, whose sum is σ = 261111447534. Its totient is φ = 261111447532.

The previous prime is 261111447469. The next prime is 261111447539. The reversal of 261111447533 is 335744111162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 239533894084 + 21577553449 = 489422^2 + 146893^2 .

It is a cyclic number.

It is not a de Polignac number, because 261111447533 - 2⁶ = 261111447469 is a prime.

It is a super-2 number, since 2×261111447533² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261111447539) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130555723766 + 130555723767.

It is an arithmetic number, because the mean of its divisors is an integer number (130555723767).

Almost surely, 2^261111447533 is an apocalyptic number.

It is an amenable number.

261111447533 is a deficient number, since it is larger than the sum of its proper divisors (1).

261111447533 is an equidigital number, since it uses as much as digits as its factorization.

261111447533 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 38.

Adding to 261111447533 its reverse (335744111162), we get a palindrome (596855558695).

The spelling of 261111447533 in words is "two hundred sixty-one billion, one hundred eleven million, four hundred forty-seven thousand, five hundred thirty-three".