261519953 has 2 divisors, whose sum is σ = 261519954. Its totient is φ = 261519952.

The previous prime is 261519949. The next prime is 261519983. The reversal of 261519953 is 359915162.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 235223569 + 26296384 = 15337^2 + 5128^2 .

It is a cyclic number.

It is not a de Polignac number, because 261519953 - 2² = 261519949 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 261519953.

It is not a weakly prime, because it can be changed into another prime (261519943) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130759976 + 130759977.

It is an arithmetic number, because the mean of its divisors is an integer number (130759977).

Almost surely, 2^261519953 is an apocalyptic number.

It is an amenable number.

261519953 is a deficient number, since it is larger than the sum of its proper divisors (1).

261519953 is an equidigital number, since it uses as much as digits as its factorization.

261519953 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72900, while the sum is 41.

The square root of 261519953 is about 16171.5785562202. The cubic root of 261519953 is about 639.4917457294.

The spelling of 261519953 in words is "two hundred sixty-one million, five hundred nineteen thousand, nine hundred fifty-three".