16551620477 has 12 divisors (see below), whose sum is σ = 19360311516. Its totient is φ = 14108713920.

The previous prime is 16551620467. The next prime is 16551620497. The reversal of 16551620477 is 77402615561.

It can be written as a sum of positive squares in 2 ways, for example, as 8030668996 + 8520951481 = 89614^2 + 92309^2 .

It is not a de Polignac number, because 16551620477 - 2¹⁴ = 16551604093 is a prime.

It is a super-2 number, since 2×16551620477² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16551620417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 924248 + ... + 941985.

It is an arithmetic number, because the mean of its divisors is an integer number (1613359293).

Almost surely, 2^16551620477 is an apocalyptic number.

It is an amenable number.

16551620477 is a deficient number, since it is larger than the sum of its proper divisors (2808691039).

16551620477 is a wasteful number, since it uses less digits than its factorization.

16551620477 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1866428 (or 1866421 counting only the distinct ones).

The product of its (nonzero) digits is 352800, while the sum is 44.

The spelling of 16551620477 in words is "sixteen billion, five hundred fifty-one million, six hundred twenty thousand, four hundred seventy-seven".