261399677 has 32 divisors (see below), whose sum is σ = 334402560. Its totient is φ = 198443520.

The previous prime is 261399673. The next prime is 261399727. The reversal of 261399677 is 776993162.

It is not a de Polignac number, because 261399677 - 2² = 261399673 is a prime.

It is a super-2 number, since 2×261399677² = 136659582271408658, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261399673) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 740333 + ... + 740685.

It is an arithmetic number, because the mean of its divisors is an integer number (10450080).

Almost surely, 2^261399677 is an apocalyptic number.

It is an amenable number.

261399677 is a deficient number, since it is larger than the sum of its proper divisors (73002883).

261399677 is a wasteful number, since it uses less digits than its factorization.

261399677 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 593.

The product of its digits is 857304, while the sum is 50.

The square root of 261399677 is about 16167.8593821198. The cubic root of 261399677 is about 639.3936941878.

The spelling of 261399677 in words is "two hundred sixty-one million, three hundred ninety-nine thousand, six hundred seventy-seven".