381699649 has 4 divisors (see below), whose sum is σ = 385077636. Its totient is φ = 378321664.

The previous prime is 381699641. The next prime is 381699667. The reversal of 381699649 is 946996183.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 946996183 = 7 ⋅135285169.

It can be written as a sum of positive squares in 2 ways, for example, as 70812225 + 310887424 = 8415^2 + 17632^2 .

It is a cyclic number.

It is not a de Polignac number, because 381699649 - 2³ = 381699641 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 381699649.

It is not an unprimeable number, because it can be changed into a prime (381699641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1688824 + ... + 1689049.

It is an arithmetic number, because the mean of its divisors is an integer number (96269409).

Almost surely, 2^381699649 is an apocalyptic number.

It is an amenable number.

381699649 is a deficient number, since it is larger than the sum of its proper divisors (3377987).

381699649 is a wasteful number, since it uses less digits than its factorization.

381699649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3377986.

The product of its digits is 2519424, while the sum is 55.

The square root of 381699649 is about 19537.1351277509. The cubic root of 381699649 is about 725.3939351006.

The spelling of 381699649 in words is "three hundred eighty-one million, six hundred ninety-nine thousand, six hundred forty-nine".