21012001274 has 16 divisors (see below), whose sum is σ = 34443722880. Its totient is φ = 9534118560.

The previous prime is 21012001273. The next prime is 21012001291. The reversal of 21012001274 is 47210021012.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (21012001273) by changing a digit.

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, 826754 + ... + 851789.

It is an arithmetic number, because the mean of its divisors is an integer number (2152732680).

Almost surely, 2^21012001274 is an apocalyptic number.

21012001274 is a deficient number, since it is larger than the sum of its proper divisors (13431721606).

21012001274 is a wasteful number, since it uses less digits than its factorization.

21012001274 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1679125.

The product of its (nonzero) digits is 224, while the sum is 20.

Adding to 21012001274 its reverse (47210021012), we get a palindrome (68222022286).

The spelling of 21012001274 in words is "twenty-one billion, twelve million, one thousand, two hundred seventy-four".