681348521 has 4 divisors (see below), whose sum is σ = 778684032. Its totient is φ = 584013012.

The previous prime is 681348517. The next prime is 681348553. The reversal of 681348521 is 125843186.

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 681348521 - 2² = 681348517 is a prime.

It is not an unprimeable number, because it can be changed into a prime (681348511) 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, 48667745 + ... + 48667758.

It is an arithmetic number, because the mean of its divisors is an integer number (194671008).

Almost surely, 2^681348521 is an apocalyptic number.

It is an amenable number.

681348521 is a deficient number, since it is larger than the sum of its proper divisors (97335511).

681348521 is an equidigital number, since it uses as much as digits as its factorization.

681348521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97335510.

The product of its digits is 46080, while the sum is 38.

The square root of 681348521 is about 26102.6535241151. The cubic root of 681348521 is about 879.9468463935.

The spelling of 681348521 in words is "six hundred eighty-one million, three hundred forty-eight thousand, five hundred twenty-one".