261367857 has 32 divisors (see below), whose sum is σ = 415324800. Its totient is φ = 161942976.

The previous prime is 261367853. The next prime is 261367867. The reversal of 261367857 is 758763162.

It is not a de Polignac number, because 261367857 - 2² = 261367853 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261367853) 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, 22383 + ... + 31995.

It is an arithmetic number, because the mean of its divisors is an integer number (12978900).

Almost surely, 2^261367857 is an apocalyptic number.

261367857 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

261367857 is a deficient number, since it is larger than the sum of its proper divisors (153956943).

261367857 is a wasteful number, since it uses less digits than its factorization.

261367857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9694 (or 9688 counting only the distinct ones).

The product of its digits is 423360, while the sum is 45.

The square root of 261367857 is about 16166.8753010593. The cubic root of 261367857 is about 639.3677488191.

The spelling of 261367857 in words is "two hundred sixty-one million, three hundred sixty-seven thousand, eight hundred fifty-seven".