19861380 has 144 divisors (see below), whose sum is σ = 75164544. Its totient is φ = 4124160.

The previous prime is 19861363. The next prime is 19861381. The reversal of 19861380 is 8316891.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (19861381) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 13144 + ... + 14576.

It is an arithmetic number, because the mean of its divisors is an integer number (521976).

Almost surely, 2^19861380 is an apocalyptic number.

19861380 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 19861380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37582272).

19861380 is an abundant number, since it is smaller than the sum of its proper divisors (55303164).

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

19861380 is a wasteful number, since it uses less digits than its factorization.

19861380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1466 (or 1461 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The square root of 19861380 is about 4456.6108198944. The cubic root of 19861380 is about 270.8131862462.

The spelling of 19861380 in words is "nineteen million, eight hundred sixty-one thousand, three hundred eighty".