3861820 has 24 divisors (see below), whose sum is σ = 8147664. Its totient is φ = 1537536.

The previous prime is 3861817. The next prime is 3861821. The reversal of 3861820 is 281683.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3861821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6787 + ... + 7333.

It is an arithmetic number, because the mean of its divisors is an integer number (339486).

Almost surely, 2^3861820 is an apocalyptic number.

It is an amenable number.

3861820 is an abundant number, since it is smaller than the sum of its proper divisors (4285844).

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

3861820 is a wasteful number, since it uses less digits than its factorization.

3861820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909 (or 907 counting only the distinct ones).

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

The square root of 3861820 is about 1965.1513936590. The cubic root of 3861820 is about 156.8907512107.

The spelling of 3861820 in words is "three million, eight hundred sixty-one thousand, eight hundred twenty".