21396352725 has 36 divisors (see below), whose sum is σ = 41807181312. Its totient is φ = 10373988000.

The previous prime is 21396352723. The next prime is 21396352729. The reversal of 21396352725 is 52725369312.

21396352725 is a `hidden beast` number, since 2 + 1 + 3 + 9 + 635 + 2 + 7 + 2 + 5 = 666.

It is not a de Polignac number, because 21396352725 - 2¹ = 21396352723 is a prime.

It is a super-2 number, since 2×21396352725² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21396352723) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 4320021 + ... + 4324970.

It is an arithmetic number, because the mean of its divisors is an integer number (1161310592).

Almost surely, 2^21396352725 is an apocalyptic number.

21396352725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21396352725 is a deficient number, since it is larger than the sum of its proper divisors (20410828587).

21396352725 is a wasteful number, since it uses less digits than its factorization.

21396352725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8645018 (or 8645010 counting only the distinct ones).

The product of its digits is 680400, while the sum is 45.

The spelling of 21396352725 in words is "twenty-one billion, three hundred ninety-six million, three hundred fifty-two thousand, seven hundred twenty-five".