1721688387020 has 48 divisors (see below), whose sum is σ = 4142840905728. Its totient is φ = 588751907520.

The previous prime is 1721688387019. The next prime is 1721688387043. The reversal of 1721688387020 is 207838861271.

It is a Smith number, since the sum of its digits (53) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16000916 + ... + 16108155.

It is an arithmetic number, because the mean of its divisors is an integer number (86309185536).

Almost surely, 2^{1721688387020} is an apocalyptic number.

1721688387020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1721688387020 is an abundant number, since it is smaller than the sum of its proper divisors (2421152518708).

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

1721688387020 is a wasteful number, since it uses less digits than its factorization.

1721688387020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32109470 (or 32109468 counting only the distinct ones).

The product of its (nonzero) digits is 1806336, while the sum is 53.

The spelling of 1721688387020 in words is "one trillion, seven hundred twenty-one billion, six hundred eighty-eight million, three hundred eighty-seven thousand, twenty".