688137261 has 16 divisors (see below), whose sum is σ = 1049800704. Its totient is φ = 392767344.

The previous prime is 688137257. The next prime is 688137301. The reversal of 688137261 is 162731886.

It is not a de Polignac number, because 688137261 - 2² = 688137257 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (688137251) 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, 156 + ... + 37098.

It is an arithmetic number, because the mean of its divisors is an integer number (65612544).

Almost surely, 2^688137261 is an apocalyptic number.

It is an amenable number.

688137261 is a deficient number, since it is larger than the sum of its proper divisors (361663443).

688137261 is a wasteful number, since it uses less digits than its factorization.

688137261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37840.

The product of its digits is 96768, while the sum is 42.

The square root of 688137261 is about 26232.3704800005. The cubic root of 688137261 is about 882.8596969892.

The spelling of 688137261 in words is "six hundred eighty-eight million, one hundred thirty-seven thousand, two hundred sixty-one".