21198407652 has 72 divisors (see below), whose sum is σ = 56991707136. Its totient is φ = 6620615424.

The previous prime is 21198407651. The next prime is 21198407663. The reversal of 21198407652 is 25670489112.

21198407652 is a `hidden beast` number, since 2 + 1 + 198 + 407 + 6 + 52 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 21198407598 and 21198407607.

It is not an unprimeable number, because it can be changed into a prime (21198407651) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 58813 + ... + 214139.

It is an arithmetic number, because the mean of its divisors is an integer number (791551488).

Almost surely, 2^21198407652 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21198407652, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28495853568).

21198407652 is an abundant number, since it is smaller than the sum of its proper divisors (35793299484).

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

21198407652 is a wasteful number, since it uses less digits than its factorization.

21198407652 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155577 (or 155572 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 45.

The spelling of 21198407652 in words is "twenty-one billion, one hundred ninety-eight million, four hundred seven thousand, six hundred fifty-two".