21506503452 has 48 divisors (see below), whose sum is σ = 58432776192. Its totient is φ = 6028776000.

The previous prime is 21506503451. The next prime is 21506503453. The reversal of 21506503452 is 25430560512.

It is an interprime number because it is at equal distance from previous prime (21506503451) and next prime (21506503453).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506503451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2410924 + ... + 2419827.

It is an arithmetic number, because the mean of its divisors is an integer number (1217349504).

Almost surely, 2^21506503452 is an apocalyptic number.

It is an amenable number.

21506503452 is an abundant number, since it is smaller than the sum of its proper divisors (36926272740).

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

21506503452 is a wasteful number, since it uses less digits than its factorization.

21506503452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4830818 (or 4830816 counting only the distinct ones).

The product of its (nonzero) digits is 36000, while the sum is 33.

The spelling of 21506503452 in words is "twenty-one billion, five hundred six million, five hundred three thousand, four hundred fifty-two".