16391401 has 4 divisors (see below), whose sum is σ = 17652292. Its totient is φ = 15130512.

The previous prime is 16391399. The next prime is 16391411. The reversal of 16391401 is 10419361.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9363600 + 7027801 = 3060^2 + 2651^2 .

It is a cyclic number.

It is not a de Polignac number, because 16391401 - 2¹ = 16391399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16391411) 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, 630426 + ... + 630451.

It is an arithmetic number, because the mean of its divisors is an integer number (4413073).

Almost surely, 2^16391401 is an apocalyptic number.

It is an amenable number.

16391401 is a deficient number, since it is larger than the sum of its proper divisors (1260891).

16391401 is a wasteful number, since it uses less digits than its factorization.

16391401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1260890.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 16391401 is about 4048.6295212084. The cubic root of 16391401 is about 254.0224059016.

The spelling of 16391401 in words is "sixteen million, three hundred ninety-one thousand, four hundred one".