16557813 has 24 divisors (see below), whose sum is σ = 26148096. Its totient is φ = 10051200.

The previous prime is 16557791. The next prime is 16557817. The reversal of 16557813 is 31875561.

It is not a de Polignac number, because 16557813 - 2¹⁰ = 16556789 is a prime.

It is a super-2 number, since 2×16557813² = 548322342685938, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16557817) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2998 + ... + 6488.

It is an arithmetic number, because the mean of its divisors is an integer number (1089504).

Almost surely, 2^16557813 is an apocalyptic number.

It is an amenable number.

16557813 is a deficient number, since it is larger than the sum of its proper divisors (9590283).

16557813 is a wasteful number, since it uses less digits than its factorization.

16557813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3545 (or 3542 counting only the distinct ones).

The product of its digits is 25200, while the sum is 36.

The square root of 16557813 is about 4069.1292680376. The cubic root of 16557813 is about 254.8791584299.

The spelling of 16557813 in words is "sixteen million, five hundred fifty-seven thousand, eight hundred thirteen".