16638420100 has 27 divisors (see below), whose sum is σ = 36108170917. Its totient is φ = 6654852080.

The previous prime is 16638420083. The next prime is 16638420109. The reversal of 16638420100 is 102483661.

It is a happy number.

The square root of 16638420100 is 128990.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 5989831236 + 10648588864 = 77394^2 + 103192^2 .

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16638420109) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 1283451 + ... + 1296349.

Almost surely, 2^16638420100 is an apocalyptic number.

16638420100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

16638420100 is the 128990-th square number.

It is an amenable number.

16638420100 is an abundant number, since it is smaller than the sum of its proper divisors (19469750817).

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

16638420100 is an frugal number, since it uses more digits than its factorization.

16638420100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25812 (or 12906 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The spelling of 16638420100 in words is "sixteen billion, six hundred thirty-eight million, four hundred twenty thousand, one hundred".