16506131421 has 64 divisors (see below), whose sum is σ = 25242721280. Its totient is φ = 9510359040.

The previous prime is 16506131417. The next prime is 16506131431. The reversal of 16506131421 is 12413160561.

It is a happy number.

It is not a de Polignac number, because 16506131421 - 2² = 16506131417 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16506131431) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 30175470 + ... + 30176016.

It is an arithmetic number, because the mean of its divisors is an integer number (394417520).

Almost surely, 2^16506131421 is an apocalyptic number.

It is an amenable number.

16506131421 is a deficient number, since it is larger than the sum of its proper divisors (8736589859).

16506131421 is a wasteful number, since it uses less digits than its factorization.

16506131421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 986.

The product of its (nonzero) digits is 4320, while the sum is 30.

Adding to 16506131421 its reverse (12413160561), we get a palindrome (28919291982).

The spelling of 16506131421 in words is "sixteen billion, five hundred six million, one hundred thirty-one thousand, four hundred twenty-one".