1221600439 has 4 divisors (see below), whose sum is σ = 1222062520. Its totient is φ = 1221138360.

The previous prime is 1221600431. The next prime is 1221600451. The reversal of 1221600439 is 9340061221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9340061221 = 1747 ⋅5346343.

It is a cyclic number.

It is not a de Polignac number, because 1221600439 - 2³ = 1221600431 is a prime.

It is a super-3 number, since 3×1221600439³ (a number of 28 digits) contains 333 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 (1221600431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 227052 + ... + 232369.

It is an arithmetic number, because the mean of its divisors is an integer number (305515630).

Almost surely, 2^1221600439 is an apocalyptic number.

1221600439 is a deficient number, since it is larger than the sum of its proper divisors (462081).

1221600439 is an equidigital number, since it uses as much as digits as its factorization.

1221600439 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462080.

The product of its (nonzero) digits is 2592, while the sum is 28.

The square root of 1221600439 is about 34951.4011021018. The cubic root of 1221600439 is about 1068.9967709686.

The spelling of 1221600439 in words is "one billion, two hundred twenty-one million, six hundred thousand, four hundred thirty-nine".