687738037621 has 8 divisors (see below), whose sum is σ = 690106009824. Its totient is φ = 685373859120.

The previous prime is 687738037619. The next prime is 687738037627. The reversal of 687738037621 is 126730837786.

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 687738037621 - 2¹ = 687738037619 is a prime.

It is a super-2 number, since 2×687738037621² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687738037627) 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, 584995 + ... + 1310608.

It is an arithmetic number, because the mean of its divisors is an integer number (86263251228).

Almost surely, 2^687738037621 is an apocalyptic number.

It is an amenable number.

687738037621 is a deficient number, since it is larger than the sum of its proper divisors (2367972203).

687738037621 is a wasteful number, since it uses less digits than its factorization.

687738037621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1896851.

The product of its (nonzero) digits is 14224896, while the sum is 58.

The spelling of 687738037621 in words is "six hundred eighty-seven billion, seven hundred thirty-eight million, thirty-seven thousand, six hundred twenty-one".