681749497 has 8 divisors (see below), whose sum is σ = 800936640. Its totient is φ = 572097360.

The previous prime is 681749473. The next prime is 681749501. The reversal of 681749497 is 794947186.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 681749497 - 2¹⁵ = 681716729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681749797) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2383597 + ... + 2383882.

It is an arithmetic number, because the mean of its divisors is an integer number (100117080).

Almost surely, 2^681749497 is an apocalyptic number.

It is an amenable number.

681749497 is a deficient number, since it is larger than the sum of its proper divisors (119187143).

681749497 is a wasteful number, since it uses less digits than its factorization.

681749497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4767503.

The product of its digits is 3048192, while the sum is 55.

The square root of 681749497 is about 26110.3331460937. Note that the first 3 decimals coincide. The cubic root of 681749497 is about 880.1194298135.

The spelling of 681749497 in words is "six hundred eighty-one million, seven hundred forty-nine thousand, four hundred ninety-seven".