21015514120 has 16 divisors (see below), whose sum is σ = 47284906860. Its totient is φ = 8406205632.

The previous prime is 21015514109. The next prime is 21015514127. The reversal of 21015514120 is 2141551012.

It can be written as a sum of positive squares in 2 ways, for example, as 20072655684 + 942858436 = 141678^2 + 30706^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21015514091 and 21015514100.

It is not an unprimeable number, because it can be changed into a prime (21015514127) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 262693887 + ... + 262693966.

Almost surely, 2^21015514120 is an apocalyptic number.

21015514120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21015514120 is an abundant number, since it is smaller than the sum of its proper divisors (26269392740).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21015514120 is a wasteful number, since it uses less digits than its factorization.

21015514120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 525387864 (or 525387860 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 22.

The spelling of 21015514120 in words is "twenty-one billion, fifteen million, five hundred fourteen thousand, one hundred twenty".