21201018 has 16 divisors (see below), whose sum is σ = 43436736. Its totient is φ = 6894560.

The previous prime is 21200987. The next prime is 21201031. The reversal of 21201018 is 81010212.

It is a junction number, because it is equal to n+sod(n) for n = 21200988 and 21201006.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42846 + ... + 43337.

It is an arithmetic number, because the mean of its divisors is an integer number (2714796).

Almost surely, 2^21201018 is an apocalyptic number.

21201018 is an abundant number, since it is smaller than the sum of its proper divisors (22235718).

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

21201018 is a wasteful number, since it uses less digits than its factorization.

21201018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86229.

The product of its (nonzero) digits is 32, while the sum is 15.

The square root of 21201018 is about 4604.4563196973. The cubic root of 21201018 is about 276.7699306467.

The spelling of 21201018 in words is "twenty-one million, two hundred one thousand, eighteen".