1720689136 has 20 divisors (see below), whose sum is σ = 3529943712. Its totient is φ = 809735936.

The previous prime is 1720689127. The next prime is 1720689137. The reversal of 1720689136 is 6319860271.

It is a super-2 number, since 2×1720689136² = 5921542205496852992, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1720689092 and 1720689101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1720689137) 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, 3162760 + ... + 3163303.

Almost surely, 2^1720689136 is an apocalyptic number.

1720689136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1720689136 is an abundant number, since it is smaller than the sum of its proper divisors (1809254576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1720689136 is a wasteful number, since it uses less digits than its factorization.

1720689136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6326088 (or 6326082 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 43.

The square root of 1720689136 is about 41481.1901468605. The cubic root of 1720689136 is about 1198.3052780951.

The spelling of 1720689136 in words is "one billion, seven hundred twenty million, six hundred eighty-nine thousand, one hundred thirty-six".