16621377 has 4 divisors (see below), whose sum is σ = 22161840. Its totient is φ = 11080916.

The previous prime is 16621361. The next prime is 16621391. The reversal of 16621377 is 77312661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 77312661 = 3 ⋅25770887.

It is a cyclic number.

It is not a de Polignac number, because 16621377 - 2⁴ = 16621361 is a prime.

It is a super-2 number, since 2×16621377² = 552540346752258, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16621307) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2770227 + ... + 2770232.

It is an arithmetic number, because the mean of its divisors is an integer number (5540460).

Almost surely, 2^16621377 is an apocalyptic number.

It is an amenable number.

16621377 is a deficient number, since it is larger than the sum of its proper divisors (5540463).

16621377 is an equidigital number, since it uses as much as digits as its factorization.

16621377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5540462.

The product of its digits is 10584, while the sum is 33.

The square root of 16621377 is about 4076.9323026020. The cubic root of 16621377 is about 255.2048949134.

The spelling of 16621377 in words is "sixteen million, six hundred twenty-one thousand, three hundred seventy-seven".