21311401424 has 10 divisors (see below), whose sum is σ = 41290840290. Its totient is φ = 10655700704.

The previous prime is 21311401373. The next prime is 21311401513. The reversal of 21311401424 is 42410411312.

It can be written as a sum of positive squares in only one way, i.e., 10718875024 + 10592526400 = 103532^2 + 102920^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21311401424.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 665981279 + ... + 665981310.

It is an arithmetic number, because the mean of its divisors is an integer number (4129084029).

Almost surely, 2^21311401424 is an apocalyptic number.

It is an amenable number.

21311401424 is a deficient number, since it is larger than the sum of its proper divisors (19979438866).

21311401424 is a wasteful number, since it uses less digits than its factorization.

21311401424 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1331962597 (or 1331962591 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 23.

Adding to 21311401424 its reverse (42410411312), we get a palindrome (63721812736).

The spelling of 21311401424 in words is "twenty-one billion, three hundred eleven million, four hundred one thousand, four hundred twenty-four".