16401557 has 4 divisors (see below), whose sum is σ = 16552140. Its totient is φ = 16250976.

The previous prime is 16401551. The next prime is 16401563. The reversal of 16401557 is 75510461.

16401557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is an interprime number because it is at equal distance from previous prime (16401551) and next prime (16401563).

It can be written as a sum of positive squares in 2 ways, for example, as 9186961 + 7214596 = 3031^2 + 2686^2 .

It is a cyclic number.

It is not a de Polignac number, because 16401557 - 2⁶ = 16401493 is a prime.

It is a super-2 number, since 2×16401557² = 538022144048498, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16401551) 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, 75128 + ... + 75345.

It is an arithmetic number, because the mean of its divisors is an integer number (4138035).

Almost surely, 2^16401557 is an apocalyptic number.

It is an amenable number.

16401557 is a deficient number, since it is larger than the sum of its proper divisors (150583).

16401557 is a wasteful number, since it uses less digits than its factorization.

16401557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 150582.

The product of its (nonzero) digits is 4200, while the sum is 29.

The square root of 16401557 is about 4049.8835785736. The cubic root of 16401557 is about 254.0748585854.

The spelling of 16401557 in words is "sixteen million, four hundred one thousand, five hundred fifty-seven".