16421601 has 16 divisors (see below), whose sum is σ = 25080704. Its totient is φ = 9362304.

The previous prime is 16421597. The next prime is 16421623. The reversal of 16421601 is 10612461.

It is not a de Polignac number, because 16421601 - 2² = 16421597 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16421501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15381 + ... + 16413.

It is an arithmetic number, because the mean of its divisors is an integer number (1567544).

Almost surely, 2^16421601 is an apocalyptic number.

It is an amenable number.

16421601 is a deficient number, since it is larger than the sum of its proper divisors (8659103).

16421601 is a wasteful number, since it uses less digits than its factorization.

16421601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1800.

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 16421601 is about 4052.3574620213. The cubic root of 16421601 is about 254.1783163104.

The spelling of 16421601 in words is "sixteen million, four hundred twenty-one thousand, six hundred one".