121620021 has 8 divisors (see below), whose sum is σ = 169210560. Its totient is φ = 77554752.

The previous prime is 121619977. The next prime is 121620029. The reversal of 121620021 is 120026121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 121620021 - 2⁶ = 121619957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121620029) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 881236 + ... + 881373.

It is an arithmetic number, because the mean of its divisors is an integer number (21151320).

Almost surely, 2^121620021 is an apocalyptic number.

It is an amenable number.

121620021 is a deficient number, since it is larger than the sum of its proper divisors (47590539).

121620021 is a wasteful number, since it uses less digits than its factorization.

121620021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1762635.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 121620021 is about 11028.1467618091. The cubic root of 121620021 is about 495.4521203341.

Adding to 121620021 its reverse (120026121), we get a palindrome (241646142).

The spelling of 121620021 in words is "one hundred twenty-one million, six hundred twenty thousand, twenty-one".