16391601 has 6 divisors (see below), whose sum is σ = 23676770. Its totient is φ = 10927728.

The previous prime is 16391569. The next prime is 16391633. The reversal of 16391601 is 10619361.

It is an interprime number because it is at equal distance from previous prime (16391569) and next prime (16391633).

It can be written as a sum of positive squares in only one way, i.e., 8856576 + 7535025 = 2976^2 + 2745^2 .

It is not a de Polignac number, because 16391601 - 2⁵ = 16391569 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16391671) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 910636 + ... + 910653.

Almost surely, 2^16391601 is an apocalyptic number.

It is an amenable number.

16391601 is a deficient number, since it is larger than the sum of its proper divisors (7285169).

16391601 is a wasteful number, since it uses less digits than its factorization.

16391601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1821295 (or 1821292 counting only the distinct ones).

The product of its (nonzero) digits is 972, while the sum is 27.

The square root of 16391601 is about 4048.6542208492. The cubic root of 16391601 is about 254.0234390505.

It can be divided in two parts, 1639 and 1601, that added together give a triangular number (3240 = T₈₀).

The spelling of 16391601 in words is "sixteen million, three hundred ninety-one thousand, six hundred one".