1688420997 has 64 divisors (see below), whose sum is σ = 2709504000. Its totient is φ = 1035768384.

The previous prime is 1688420969. The next prime is 1688420999. The reversal of 1688420997 is 7990248861.

It is not a de Polignac number, because 1688420997 - 2²⁷ = 1554203269 is a prime.

It is a super-2 number, since 2×1688420997² = 5701530926220948018, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1688420999) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 5762383 + ... + 5762675.

It is an arithmetic number, because the mean of its divisors is an integer number (42336000).

Almost surely, 2^1688420997 is an apocalyptic number.

It is an amenable number.

1688420997 is a deficient number, since it is larger than the sum of its proper divisors (1021083003).

1688420997 is a wasteful number, since it uses less digits than its factorization.

1688420997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 607 (or 601 counting only the distinct ones).

The product of its (nonzero) digits is 1741824, while the sum is 54.

The square root of 1688420997 is about 41090.4003022604. The cubic root of 1688420997 is about 1190.7673409338.

The spelling of 1688420997 in words is "one billion, six hundred eighty-eight million, four hundred twenty thousand, nine hundred ninety-seven".