21013001444 has 6 divisors (see below), whose sum is σ = 36772752534. Its totient is φ = 10506500720.

The previous prime is 21013001407. The next prime is 21013001461. The reversal of 21013001444 is 44410031012.

It can be written as a sum of positive squares in only one way, i.e., 18109084900 + 2903916544 = 134570^2 + 53888^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2626625177 + ... + 2626625184.

It is an arithmetic number, because the mean of its divisors is an integer number (6128792089).

Almost surely, 2^21013001444 is an apocalyptic number.

It is an amenable number.

21013001444 is a deficient number, since it is larger than the sum of its proper divisors (15759751090).

21013001444 is a wasteful number, since it uses less digits than its factorization.

21013001444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5253250365 (or 5253250363 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21013001444 its reverse (44410031012), we get a palindrome (65423032456).

The spelling of 21013001444 in words is "twenty-one billion, thirteen million, one thousand, four hundred forty-four".