20442440421 has 32 divisors (see below), whose sum is σ = 32632064640. Its totient is φ = 12573273600.

The previous prime is 20442440407. The next prime is 20442440437. The reversal of 20442440421 is 12404424402.

It is not a de Polignac number, because 20442440421 - 2¹³ = 20442432229 is a prime.

It is a super-2 number, since 2×20442440421² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20442440021) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 691381 + ... + 720341.

It is an arithmetic number, because the mean of its divisors is an integer number (1019752020).

Almost surely, 2^20442440421 is an apocalyptic number.

It is an amenable number.

20442440421 is a deficient number, since it is larger than the sum of its proper divisors (12189624219).

20442440421 is a wasteful number, since it uses less digits than its factorization.

20442440421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30994 (or 30988 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 27.

Adding to 20442440421 its reverse (12404424402), we get a palindrome (32846864823).

The spelling of 20442440421 in words is "twenty billion, four hundred forty-two million, four hundred forty thousand, four hundred twenty-one".