388221749 has 4 divisors (see below), whose sum is σ = 388284864. Its totient is φ = 388158636.

The previous prime is 388221731. The next prime is 388221781. The reversal of 388221749 is 947122883.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 947122883 = 7 ⋅135303269.

It is a cyclic number.

It is not a de Polignac number, because 388221749 - 2²⁰ = 387173173 is a prime.

It is a super-2 number, since 2×388221749² = 301432252793238002, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (388221709) 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, 21197 + ... + 35010.

It is an arithmetic number, because the mean of its divisors is an integer number (97071216).

Almost surely, 2^388221749 is an apocalyptic number.

It is an amenable number.

388221749 is a deficient number, since it is larger than the sum of its proper divisors (63115).

388221749 is an equidigital number, since it uses as much as digits as its factorization.

388221749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63114.

The product of its digits is 193536, while the sum is 44.

The square root of 388221749 is about 19703.3435995011. The cubic root of 388221749 is about 729.5022246102.

The spelling of 388221749 in words is "three hundred eighty-eight million, two hundred twenty-one thousand, seven hundred forty-nine".