120021915 has 16 divisors (see below), whose sum is σ = 206807328. Its totient is φ = 59087616.

The previous prime is 120021911. The next prime is 120021931. The reversal of 120021915 is 519120021.

It is not a de Polignac number, because 120021915 - 2² = 120021911 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 120021891 and 120021900.

It is not an unprimeable number, because it can be changed into a prime (120021911) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 307554 + ... + 307943.

It is an arithmetic number, because the mean of its divisors is an integer number (12925458).

Almost surely, 2^120021915 is an apocalyptic number.

120021915 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

120021915 is a deficient number, since it is larger than the sum of its proper divisors (86785413).

120021915 is a wasteful number, since it uses less digits than its factorization.

120021915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 615518.

The product of its (nonzero) digits is 180, while the sum is 21.

The square root of 120021915 is about 10955.4513827592. The cubic root of 120021915 is about 493.2724391704.

Adding to 120021915 its reverse (519120021), we get a palindrome (639141936).

The spelling of 120021915 in words is "one hundred twenty million, twenty-one thousand, nine hundred fifteen".