21555340430 has 32 divisors (see below), whose sum is σ = 42113240064. Its totient is φ = 7896220416.

The previous prime is 21555340421. The next prime is 21555340463. The reversal of 21555340430 is 3404355512.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 636287 + ... + 669306.

It is an arithmetic number, because the mean of its divisors is an integer number (1316038752).

Almost surely, 2^21555340430 is an apocalyptic number.

21555340430 is a deficient number, since it is larger than the sum of its proper divisors (20557899634).

21555340430 is a wasteful number, since it uses less digits than its factorization.

21555340430 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1305740.

The product of its (nonzero) digits is 36000, while the sum is 32.

Adding to 21555340430 its reverse (3404355512), we get a palindrome (24959695942).

The spelling of 21555340430 in words is "twenty-one billion, five hundred fifty-five million, three hundred forty thousand, four hundred thirty".