16620390 has 120 divisors (see below), whose sum is σ = 48142512. Its totient is φ = 4112640.

The previous prime is 16620361. The next prime is 16620391. The reversal of 16620390 is 9302661.

It is a happy number.

16620390 is a `hidden beast` number, since 1 + 6 + 620 + 39 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16620391) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 234055 + ... + 234125.

It is a vampire number, since it can be written as 2601 ⋅ 6390 (with its own digits).

Almost surely, 2^16620390 is an apocalyptic number.

16620390 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 16620390, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24071256).

16620390 is an abundant number, since it is smaller than the sum of its proper divisors (31522122).

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

16620390 is a wasteful number, since it uses less digits than its factorization.

16620390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124 (or 98 counting only the distinct ones).

The product of its (nonzero) digits is 1944, while the sum is 27.

The square root of 16620390 is about 4076.8112539091. The cubic root of 16620390 is about 255.1998433420.

It can be divided in two parts, 16620 and 390, that multiplied together give a triangular number (6481800 = T₃₆₀₀).

The spelling of 16620390 in words is "sixteen million, six hundred twenty thousand, three hundred ninety".