1257706137 has 4 divisors (see below), whose sum is σ = 1676941520. Its totient is φ = 838470756.

The previous prime is 1257706091. The next prime is 1257706139. The reversal of 1257706137 is 7316077521.

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 not a de Polignac number, because 1257706137 - 2¹⁴ = 1257689753 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1257706095 and 1257706104.

It is not an unprimeable number, because it can be changed into a prime (1257706139) 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, 209617687 + ... + 209617692.

It is an arithmetic number, because the mean of its divisors is an integer number (419235380).

Almost surely, 2^1257706137 is an apocalyptic number.

It is an amenable number.

1257706137 is a deficient number, since it is larger than the sum of its proper divisors (419235383).

1257706137 is an equidigital number, since it uses as much as digits as its factorization.

1257706137 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 419235382.

The product of its (nonzero) digits is 61740, while the sum is 39.

The square root of 1257706137 is about 35464.1528448094. The cubic root of 1257706137 is about 1079.4264607337.

The spelling of 1257706137 in words is "one billion, two hundred fifty-seven million, seven hundred six thousand, one hundred thirty-seven".