261977 has 2 divisors, whose sum is σ = 261978. Its totient is φ = 261976.

The previous prime is 261973. The next prime is 261983. The reversal of 261977 is 779162.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 143641 + 118336 = 379^2 + 344^2 .

It is a cyclic number.

It is not a de Polignac number, because 261977 - 2² = 261973 is a prime.

It is a Chen prime.

It is a nialpdrome in base 8.

It is not a weakly prime, because it can be changed into another prime (261971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130988 + 130989.

It is an arithmetic number, because the mean of its divisors is an integer number (130989).

2²⁶¹⁹⁷⁷ is an apocalyptic number.

It is an amenable number.

261977 is a deficient number, since it is larger than the sum of its proper divisors (1).

261977 is an equidigital number, since it uses as much as digits as its factorization.

261977 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5292, while the sum is 32.

The square root of 261977 is about 511.8368880806. The cubic root of 261977 is about 63.9864066182.

The spelling of 261977 in words is "two hundred sixty-one thousand, nine hundred seventy-seven".