381445820 has 48 divisors (see below), whose sum is σ = 917027328. Its totient is φ = 130559040.

The previous prime is 381445789. The next prime is 381445861. The reversal of 381445820 is 28544183.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 94769 + ... + 98711.

It is an arithmetic number, because the mean of its divisors is an integer number (19104736).

Almost surely, 2^381445820 is an apocalyptic number.

It is an amenable number.

381445820 is an abundant number, since it is smaller than the sum of its proper divisors (535581508).

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

381445820 is a wasteful number, since it uses less digits than its factorization.

381445820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4650 (or 4648 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 35.

The square root of 381445820 is about 19530.6379824111. The cubic root of 381445820 is about 725.2331045915.

The spelling of 381445820 in words is "three hundred eighty-one million, four hundred forty-five thousand, eight hundred twenty".