261380401 has 2 divisors, whose sum is σ = 261380402. Its totient is φ = 261380400.

The previous prime is 261380387. The next prime is 261380407. The reversal of 261380401 is 104083162.

261380401 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 252047376 + 9333025 = 15876^2 + 3055^2 .

It is a cyclic number.

It is not a de Polignac number, because 261380401 - 2¹⁵ = 261347633 is a prime.

It is not a weakly prime, because it can be changed into another prime (261380407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130690200 + 130690201.

It is an arithmetic number, because the mean of its divisors is an integer number (130690201).

Almost surely, 2^261380401 is an apocalyptic number.

It is an amenable number.

261380401 is a deficient number, since it is larger than the sum of its proper divisors (1).

261380401 is an equidigital number, since it uses as much as digits as its factorization.

261380401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 261380401 is about 16167.2632501608. The cubic root of 261380401 is about 639.3779771882.

The spelling of 261380401 in words is "two hundred sixty-one million, three hundred eighty thousand, four hundred one".