121920647 has 4 divisors (see below), whose sum is σ = 121959336. Its totient is φ = 121881960.

The previous prime is 121920619. The next prime is 121920649. The reversal of 121920647 is 746029121.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 121920647 - 2¹⁸ = 121658503 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121920649) 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, 14153 + ... + 21074.

It is an arithmetic number, because the mean of its divisors is an integer number (30489834).

Almost surely, 2^121920647 is an apocalyptic number.

121920647 is a deficient number, since it is larger than the sum of its proper divisors (38689).

121920647 is an equidigital number, since it uses as much as digits as its factorization.

121920647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38688.

The product of its (nonzero) digits is 6048, while the sum is 32.

The square root of 121920647 is about 11041.7682913562. The cubic root of 121920647 is about 495.8600116019.

Adding to 121920647 its reverse (746029121), we get a palindrome (867949768).

The spelling of 121920647 in words is "one hundred twenty-one million, nine hundred twenty thousand, six hundred forty-seven".