1685389217401 has 4 divisors (see below), whose sum is σ = 1713955136400. Its totient is φ = 1656823298404.

The previous prime is 1685389217389. The next prime is 1685389217423. The reversal of 1685389217401 is 1047129835861.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1685389217401 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1685389217431) 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, 14282959411 + ... + 14282959528.

It is an arithmetic number, because the mean of its divisors is an integer number (428488784100).

It is a 1-persistent number, because it is pandigital, but 2⋅1685389217401 = 3370778434802 is not.

Almost surely, 2^{1685389217401} is an apocalyptic number.

It is an amenable number.

1685389217401 is a deficient number, since it is larger than the sum of its proper divisors (28565918999).

1685389217401 is an equidigital number, since it uses as much as digits as its factorization.

1685389217401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28565918998.

The product of its (nonzero) digits is 2903040, while the sum is 55.

The spelling of 1685389217401 in words is "one trillion, six hundred eighty-five billion, three hundred eighty-nine million, two hundred seventeen thousand, four hundred one".