16506401 has 2 divisors, whose sum is σ = 16506402. Its totient is φ = 16506400.

The previous prime is 16506397. The next prime is 16506407. The reversal of 16506401 is 10460561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16483600 + 22801 = 4060^2 + 151^2 .

It is a cyclic number.

It is not a de Polignac number, because 16506401 - 2² = 16506397 is a prime.

It is a super-2 number, since 2×16506401² = 544922547945602, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16506407) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8253200 + 8253201.

It is an arithmetic number, because the mean of its divisors is an integer number (8253201).

Almost surely, 2^16506401 is an apocalyptic number.

It is an amenable number.

16506401 is a deficient number, since it is larger than the sum of its proper divisors (1).

16506401 is an equidigital number, since it uses as much as digits as its factorization.

16506401 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 16506401 is about 4062.8070345514. The cubic root of 16506401 is about 254.6150850442.

Adding to 16506401 its reverse (10460561), we get a palindrome (26966962).

The spelling of 16506401 in words is "sixteen million, five hundred six thousand, four hundred one".