21377018 has 16 divisors (see below), whose sum is σ = 34613376. Its totient is φ = 9843120.

The previous prime is 21376991. The next prime is 21377029. The reversal of 21377018 is 81077312.

It is a super-3 number, since 3×21377018³ (a number of 23 digits) contains 333 as substring.

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, 15755 + ... + 17057.

It is an arithmetic number, because the mean of its divisors is an integer number (2163336).

Almost surely, 2^21377018 is an apocalyptic number.

21377018 is a deficient number, since it is larger than the sum of its proper divisors (13236358).

21377018 is a wasteful number, since it uses less digits than its factorization.

21377018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1949.

The product of its (nonzero) digits is 2352, while the sum is 29.

The square root of 21377018 is about 4623.5287389612. The cubic root of 21377018 is about 277.5336885216.

The spelling of 21377018 in words is "twenty-one million, three hundred seventy-seven thousand, eighteen".