16421860 has 72 divisors (see below), whose sum is σ = 43235640. Its totient is φ = 5193216.

The previous prime is 16421857. The next prime is 16421863. The reversal of 16421860 is 6812461.

It is an interprime number because it is at equal distance from previous prime (16421857) and next prime (16421863).

It can be written as a sum of positive squares in 4 ways, for example, as 1382976 + 15038884 = 1176^2 + 3878^2 .

It is a Harshad number since it is a multiple of its sum of digits (28).

It is not an unprimeable number, because it can be changed into a prime (16421863) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12096 + ... + 13384.

It is an arithmetic number, because the mean of its divisors is an integer number (600495).

Almost surely, 2^16421860 is an apocalyptic number.

16421860 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16421860, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21617820).

16421860 is an abundant number, since it is smaller than the sum of its proper divisors (26813780).

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

16421860 is a wasteful number, since it uses less digits than its factorization.

16421860 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1325 (or 1316 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 16421860 is about 4052.3894186023. The cubic root of 16421860 is about 254.1796525958.

The spelling of 16421860 in words is "sixteen million, four hundred twenty-one thousand, eight hundred sixty".