681437797 has 4 divisors (see below), whose sum is σ = 681673536. Its totient is φ = 681202060.

The previous prime is 681437791. The next prime is 681437839. The reversal of 681437797 is 797734186.

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 681437797 - 2¹⁹ = 680913509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681437791) 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, 113479 + ... + 119332.

It is an arithmetic number, because the mean of its divisors is an integer number (170418384).

Almost surely, 2^681437797 is an apocalyptic number.

It is an amenable number.

681437797 is a deficient number, since it is larger than the sum of its proper divisors (235739).

681437797 is a wasteful number, since it uses less digits than its factorization.

681437797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 235738.

The product of its digits is 1778112, while the sum is 52.

The square root of 681437797 is about 26104.3635624391. The cubic root of 681437797 is about 879.9852773880.

The spelling of 681437797 in words is "six hundred eighty-one million, four hundred thirty-seven thousand, seven hundred ninety-seven".