21145994234 has 16 divisors (see below), whose sum is σ = 31914673920. Its totient is φ = 10507838400.

The previous prime is 21145994203. The next prime is 21145994279. The reversal of 21145994234 is 43249954112.

It is a super-2 number, since 2×21145994234² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 636434 + ... + 668834.

It is an arithmetic number, because the mean of its divisors is an integer number (1994667120).

Almost surely, 2^21145994234 is an apocalyptic number.

21145994234 is a deficient number, since it is larger than the sum of its proper divisors (10768679686).

21145994234 is a wasteful number, since it uses less digits than its factorization.

21145994234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34405.

The product of its digits is 311040, while the sum is 44.

The spelling of 21145994234 in words is "twenty-one billion, one hundred forty-five million, nine hundred ninety-four thousand, two hundred thirty-four".