16478621 has 4 divisors (see below), whose sum is σ = 16604544. Its totient is φ = 16352700.

The previous prime is 16478599. The next prime is 16478659. The reversal of 16478621 is 12687461.

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: 12687461 = 1319 ⋅9619.

It is a cyclic number.

It is not a de Polignac number, because 16478621 - 2¹⁸ = 16216477 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 (16478221) 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, 62765 + ... + 63026.

It is an arithmetic number, because the mean of its divisors is an integer number (4151136).

Almost surely, 2^16478621 is an apocalyptic number.

It is an amenable number.

16478621 is a deficient number, since it is larger than the sum of its proper divisors (125923).

16478621 is a wasteful number, since it uses less digits than its factorization.

16478621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 125922.

The product of its digits is 16128, while the sum is 35.

The square root of 16478621 is about 4059.3867763494. The cubic root of 16478621 is about 254.4721671784.

The spelling of 16478621 in words is "sixteen million, four hundred seventy-eight thousand, six hundred twenty-one".