261651401 has 8 divisors (see below), whose sum is σ = 289459008. Its totient is φ = 234514000.

The previous prime is 261651361. The next prime is 261651421. The reversal of 261651401 is 104156162.

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

It is a cyclic number.

It is not a de Polignac number, because 261651401 - 2¹⁰ = 261650377 is a prime.

It is a super-2 number, since 2×261651401² = 136922911290525602, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261651421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 166730 + ... + 168291.

It is an arithmetic number, because the mean of its divisors is an integer number (36182376).

Almost surely, 2^261651401 is an apocalyptic number.

It is an amenable number.

261651401 is a deficient number, since it is larger than the sum of its proper divisors (27807607).

261651401 is a wasteful number, since it uses less digits than its factorization.

261651401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 335103.

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 261651401 is about 16175.6422129077. The cubic root of 261651401 is about 639.5988705463.

The spelling of 261651401 in words is "two hundred sixty-one million, six hundred fifty-one thousand, four hundred one".