21437347640225 has 24 divisors (see below), whose sum is σ = 30704701567968. Its totient is φ = 14673692499200.

The previous prime is 21437347640221. The next prime is 21437347640237. The reversal of 21437347640225 is 52204674373412.

It is not a de Polignac number, because 21437347640225 - 2² = 21437347640221 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21437347640221) 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, 2292759779 + ... + 2292769128.

It is an arithmetic number, because the mean of its divisors is an integer number (1279362565332).

Almost surely, 2^{21437347640225} is an apocalyptic number.

21437347640225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21437347640225 is a deficient number, since it is larger than the sum of its proper divisors (9267353927743).

21437347640225 is a wasteful number, since it uses less digits than its factorization.

21437347640225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4585528945 (or 4585528940 counting only the distinct ones).

The product of its (nonzero) digits is 6773760, while the sum is 50.

The spelling of 21437347640225 in words is "twenty-one trillion, four hundred thirty-seven billion, three hundred forty-seven million, six hundred forty thousand, two hundred twenty-five".