4001221375 has 16 divisors (see below), whose sum is σ = 4995293472. Its totient is φ = 3199843200.

The previous prime is 4001221369. The next prime is 4001221387. The reversal of 4001221375 is 5731221004.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-4001221375 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 659104 + ... + 665146.

It is an arithmetic number, because the mean of its divisors is an integer number (312205842).

Almost surely, 2^4001221375 is an apocalyptic number.

4001221375 is a deficient number, since it is larger than the sum of its proper divisors (994072097).

4001221375 is an equidigital number, since it uses as much as digits as its factorization.

4001221375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11355 (or 11345 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 25.

The square root of 4001221375 is about 63255.2082835872. The cubic root of 4001221375 is about 1587.5626031898.

Adding to 4001221375 its reverse (5731221004), we get a palindrome (9732442379).

The spelling of 4001221375 in words is "four billion, one million, two hundred twenty-one thousand, three hundred seventy-five".