7551661557 has 32 divisors (see below), whose sum is σ = 11397585024. Its totient is φ = 4407091200.

The previous prime is 7551661531. The next prime is 7551661561.

7551661557 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 7551661557 - 2⁶ = 7551661493 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7551661457) 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, 86557 + ... + 150317.

It is an arithmetic number, because the mean of its divisors is an integer number (356174532).

Almost surely, 2^7551661557 is an apocalyptic number.

It is an amenable number.

7551661557 is a deficient number, since it is larger than the sum of its proper divisors (3845923467).

7551661557 is a wasteful number, since it uses less digits than its factorization.

7551661557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63909.

The product of its digits is 1102500, while the sum is 48.

The square root of 7551661557 is about 86900.2966450633. The cubic root of 7551661557 is about 1961.9179439393.

The spelling of 7551661557 in words is "seven billion, five hundred fifty-one million, six hundred sixty-one thousand, five hundred fifty-seven".