21346164425 has 6 divisors (see below), whose sum is σ = 26469243918. Its totient is φ = 17076931520.

The previous prime is 21346164421. The next prime is 21346164457. The reversal of 21346164425 is 52446164312.

It can be written as a sum of positive squares in 3 ways, for example, as 79192201 + 21266972224 = 8899^2 + 145832^2 .

It is not a de Polignac number, because 21346164425 - 2² = 21346164421 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21346164421) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 426923264 + ... + 426923313.

It is an arithmetic number, because the mean of its divisors is an integer number (4411540653).

Almost surely, 2^21346164425 is an apocalyptic number.

21346164425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21346164425 is a deficient number, since it is larger than the sum of its proper divisors (5123079493).

21346164425 is an equidigital number, since it uses as much as digits as its factorization.

21346164425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 853846587 (or 853846582 counting only the distinct ones).

The product of its digits is 138240, while the sum is 38.

The spelling of 21346164425 in words is "twenty-one billion, three hundred forty-six million, one hundred sixty-four thousand, four hundred twenty-five".