261048649 has 9 divisors (see below), whose sum is σ = 265267821. Its totient is φ = 256896300.

The previous prime is 261048647. The next prime is 261048661. The reversal of 261048649 is 946840162.

The square root of 261048649 is 16157.

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

It is not a de Polignac number, because 261048649 - 2¹ = 261048647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261048647) 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, 1728724 + ... + 1728874.

Almost surely, 2^261048649 is an apocalyptic number.

261048649 is the 16157-th square number.

261048649 is the 8079-th centered octagonal number.

It is an amenable number.

261048649 is a deficient number, since it is larger than the sum of its proper divisors (4219172).

261048649 is an frugal number, since it uses more digits than its factorization.

261048649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 516 (or 258 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 40.

The cubic root of 261048649 is about 639.1073566340.

Multiplying 261048649 by its product of nonzero digits (82944), we get a square (21652419142656 = 4653216²).

The spelling of 261048649 in words is "two hundred sixty-one million, forty-eight thousand, six hundred forty-nine".