21021400324 has 24 divisors (see below), whose sum is σ = 37436624568. Its totient is φ = 10326343680.

The previous prime is 21021400307. The next prime is 21021400327. The reversal of 21021400324 is 42300412012.

It can be written as a sum of positive squares in 4 ways, for example, as 7418376900 + 13603023424 = 86130^2 + 116632^2 .

It is not an unprimeable number, because it can be changed into a prime (21021400327) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 65017 + ... + 215104.

It is an arithmetic number, because the mean of its divisors is an integer number (1559859357).

Almost surely, 2^21021400324 is an apocalyptic number.

It is an amenable number.

21021400324 is a deficient number, since it is larger than the sum of its proper divisors (16415224244).

21021400324 is a wasteful number, since it uses less digits than its factorization.

21021400324 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 280455 (or 280453 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 21021400324 its reverse (42300412012), we get a palindrome (63321812336).

The spelling of 21021400324 in words is "twenty-one billion, twenty-one million, four hundred thousand, three hundred twenty-four".