21021433040 has 40 divisors (see below), whose sum is σ = 48968738568. Its totient is φ = 8392417280.

The previous prime is 21021433001. The next prime is 21021433063. The reversal of 21021433040 is 4033412012.

It can be written as a sum of positive squares in 4 ways, for example, as 78712384 + 20942720656 = 8872^2 + 144716^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 210497 + ... + 293856.

Almost surely, 2^21021433040 is an apocalyptic number.

21021433040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21021433040 is an abundant number, since it is smaller than the sum of its proper divisors (27947305528).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21021433040 is a wasteful number, since it uses less digits than its factorization.

21021433040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 504887 (or 504881 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21021433040 its reverse (4033412012), we get a palindrome (25054845052).

The spelling of 21021433040 in words is "twenty-one billion, twenty-one million, four hundred thirty-three thousand, forty".