1557678261 has 16 divisors (see below), whose sum is σ = 2201278464. Its totient is φ = 976387584.

The previous prime is 1557678229. The next prime is 1557678263. The reversal of 1557678261 is 1628767551.

It is not a de Polignac number, because 1557678261 - 2⁵ = 1557678229 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1557678261.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1557678263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 37900 + ... + 67466.

It is an arithmetic number, because the mean of its divisors is an integer number (137579904).

Almost surely, 2^1557678261 is an apocalyptic number.

It is an amenable number.

1557678261 is a deficient number, since it is larger than the sum of its proper divisors (643600203).

1557678261 is a wasteful number, since it uses less digits than its factorization.

1557678261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30620.

The product of its digits is 705600, while the sum is 48.

The square root of 1557678261 is about 39467.4329162665. The cubic root of 1557678261 is about 1159.2023502215.

The spelling of 1557678261 in words is "one billion, five hundred fifty-seven million, six hundred seventy-eight thousand, two hundred sixty-one".