16551621456 has 40 divisors (see below), whose sum is σ = 43095051264. Its totient is φ = 5473762560.

The previous prime is 16551621439. The next prime is 16551621479. The reversal of 16551621456 is 65412615561.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1351485 + ... + 1363676.

Almost surely, 2^16551621456 is an apocalyptic number.

16551621456 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

16551621456 is an abundant number, since it is smaller than the sum of its proper divisors (26543429808).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16551621456 is a wasteful number, since it uses less digits than its factorization.

16551621456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2715299 (or 2715293 counting only the distinct ones).

The product of its digits is 216000, while the sum is 42.

The spelling of 16551621456 in words is "sixteen billion, five hundred fifty-one million, six hundred twenty-one thousand, four hundred fifty-six".