261428712601 has 9 divisors (see below), whose sum is σ = 304115114901. Its totient is φ = 224078685852.

The previous prime is 261428712581. The next prime is 261428712617. The reversal of 261428712601 is 106217824162.

The square root of 261428712601 is 511301.

It is a perfect power (a square), and thus also a powerful number.

It is not a de Polignac number, because 261428712601 - 2¹¹ = 261428710553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261428712901) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3542586 + ... + 3615628.

Almost surely, 2^261428712601 is an apocalyptic number.

261428712601 is the 511301-st square number.

261428712601 is the 255651-st centered octagonal number.

It is an amenable number.

261428712601 is a deficient number, since it is larger than the sum of its proper divisors (42686402300).

261428712601 is an frugal number, since it uses more digits than its factorization.

261428712601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146100 (or 73050 counting only the distinct ones).

The product of its (nonzero) digits is 64512, while the sum is 40.

The spelling of 261428712601 in words is "two hundred sixty-one billion, four hundred twenty-eight million, seven hundred twelve thousand, six hundred one".