487691721 has 24 divisors (see below), whose sum is σ = 793278720. Its totient is φ = 286034400.

The previous prime is 487691719. The next prime is 487691723. The reversal of 487691721 is 127196784.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (487691719) and next prime (487691723).

It is not a de Polignac number, because 487691721 - 2¹ = 487691719 is a prime.

It is not an unprimeable number, because it can be changed into a prime (487691723) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 76386 + ... + 82523.

It is an arithmetic number, because the mean of its divisors is an integer number (33053280).

Almost surely, 2^487691721 is an apocalyptic number.

It is an amenable number.

487691721 is a deficient number, since it is larger than the sum of its proper divisors (305586999).

487691721 is a wasteful number, since it uses less digits than its factorization.

487691721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158957 (or 158954 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 487691721 is about 22083.7433647468. The cubic root of 487691721 is about 787.1336176254.

The spelling of 487691721 in words is "four hundred eighty-seven million, six hundred ninety-one thousand, seven hundred twenty-one".