21345421004 has 12 divisors (see below), whose sum is σ = 37601868528. Its totient is φ = 10602030000.

The previous prime is 21345420997. The next prime is 21345421007. The reversal of 21345421004 is 40012454312.

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21345421007) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17669447 + ... + 17670654.

It is an arithmetic number, because the mean of its divisors is an integer number (3133489044).

Almost surely, 2^21345421004 is an apocalyptic number.

It is an amenable number.

21345421004 is a deficient number, since it is larger than the sum of its proper divisors (16256447524).

21345421004 is a wasteful number, since it uses less digits than its factorization.

21345421004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35340256 (or 35340254 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 26.

Adding to 21345421004 its reverse (40012454312), we get a palindrome (61357875316).

The spelling of 21345421004 in words is "twenty-one billion, three hundred forty-five million, four hundred twenty-one thousand, four".