261153421 has 2 divisors, whose sum is σ = 261153422. Its totient is φ = 261153420.

The previous prime is 261153413. The next prime is 261153463. The reversal of 261153421 is 124351162.

It is a happy number.

261153421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 237006025 + 24147396 = 15395^2 + 4914^2 .

It is a cyclic number.

It is not a de Polignac number, because 261153421 - 2³ = 261153413 is a prime.

It is a super-2 number, since 2×261153421² = 136402218600006482, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261153401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130576710 + 130576711.

It is an arithmetic number, because the mean of its divisors is an integer number (130576711).

Almost surely, 2^261153421 is an apocalyptic number.

It is an amenable number.

261153421 is a deficient number, since it is larger than the sum of its proper divisors (1).

261153421 is an equidigital number, since it uses as much as digits as its factorization.

261153421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1440, while the sum is 25.

The square root of 261153421 is about 16160.2419845744. The cubic root of 261153421 is about 639.1928472121.

The spelling of 261153421 in words is "two hundred sixty-one million, one hundred fifty-three thousand, four hundred twenty-one".