1261657 has 4 divisors (see below), whose sum is σ = 1328080. Its totient is φ = 1195236.

The previous prime is 1261649. The next prime is 1261697. The reversal of 1261657 is 7561621.

1261657 is nontrivially palindromic in base 2.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1261657 - 2³ = 1261649 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1261627) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33183 + ... + 33220.

It is an arithmetic number, because the mean of its divisors is an integer number (332020).

2^1261657 is an apocalyptic number.

1261657 is the 649-th hex number.

It is an amenable number.

1261657 is a deficient number, since it is larger than the sum of its proper divisors (66423).

1261657 is an equidigital number, since it uses as much as digits as its factorization.

1261657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66422.

The product of its digits is 2520, while the sum is 28.

The square root of 1261657 is about 1123.2350599941. The cubic root of 1261657 is about 108.0555555507.

The spelling of 1261657 in words is "one million, two hundred sixty-one thousand, six hundred fifty-seven".