21151018 has 16 divisors (see below), whose sum is σ = 36854784. Its totient is φ = 8915760.

The previous prime is 21150991. The next prime is 21151027. The reversal of 21151018 is 81015112.

It is a happy number.

It is a super-3 number, since 3×21151018³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21150986 and 21151004.

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, 11530 + ... + 13237.

It is an arithmetic number, because the mean of its divisors is an integer number (2303424).

Almost surely, 2^21151018 is an apocalyptic number.

21151018 is a deficient number, since it is larger than the sum of its proper divisors (15703766).

21151018 is a wasteful number, since it uses less digits than its factorization.

21151018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24837.

The product of its (nonzero) digits is 80, while the sum is 19.

The square root of 21151018 is about 4599.0235920247. The cubic root of 21151018 is about 276.5521834044.

The spelling of 21151018 in words is "twenty-one million, one hundred fifty-one thousand, eighteen".