261577451 has 4 divisors (see below), whose sum is σ = 263309904. Its totient is φ = 259845000.

The previous prime is 261577429. The next prime is 261577489. The reversal of 261577451 is 154775162.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 154775162 = 2 ⋅77387581.

It is a cyclic number.

It is not a de Polignac number, because 261577451 - 2¹⁴ = 261561067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261577051) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 866000 + ... + 866301.

It is an arithmetic number, because the mean of its divisors is an integer number (65827476).

Almost surely, 2^261577451 is an apocalyptic number.

261577451 is a deficient number, since it is larger than the sum of its proper divisors (1732453).

261577451 is a wasteful number, since it uses less digits than its factorization.

261577451 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1732452.

The product of its digits is 58800, while the sum is 38.

The square root of 261577451 is about 16173.3562070462. The cubic root of 261577451 is about 639.5386086954.

The spelling of 261577451 in words is "two hundred sixty-one million, five hundred seventy-seven thousand, four hundred fifty-one".