21841800725 has 6 divisors (see below), whose sum is σ = 27083832930. Its totient is φ = 17473440560.

The previous prime is 21841800709. The next prime is 21841800733. The reversal of 21841800725 is 52700814812.

It can be written as a sum of positive squares in 3 ways, for example, as 1548658609 + 20293142116 = 39353^2 + 142454^2 .

It is not a de Polignac number, because 21841800725 - 2⁴ = 21841800709 is a prime.

It is a super-2 number, since 2×21841800725² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 436835990 + ... + 436836039.

It is an arithmetic number, because the mean of its divisors is an integer number (4513972155).

Almost surely, 2^21841800725 is an apocalyptic number.

21841800725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21841800725 is a deficient number, since it is larger than the sum of its proper divisors (5242032205).

21841800725 is an equidigital number, since it uses as much as digits as its factorization.

21841800725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 873672039 (or 873672034 counting only the distinct ones).

The product of its (nonzero) digits is 35840, while the sum is 38.

The spelling of 21841800725 in words is "twenty-one billion, eight hundred forty-one million, eight hundred thousand, seven hundred twenty-five".