21055540652 has 12 divisors (see below), whose sum is σ = 37745908536. Its totient is φ = 10270995360.

The previous prime is 21055540651. The next prime is 21055540657. The reversal of 21055540652 is 25604555012.

It is not an unprimeable number, because it can be changed into a prime (21055540651) 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, 64193558 + ... + 64193885.

It is an arithmetic number, because the mean of its divisors is an integer number (3145492378).

Almost surely, 2^21055540652 is an apocalyptic number.

It is an amenable number.

21055540652 is a deficient number, since it is larger than the sum of its proper divisors (16690367884).

21055540652 is a wasteful number, since it uses less digits than its factorization.

21055540652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128387488 (or 128387486 counting only the distinct ones).

The product of its (nonzero) digits is 60000, while the sum is 35.

The spelling of 21055540652 in words is "twenty-one billion, fifty-five million, five hundred forty thousand, six hundred fifty-two".