21002220425 has 12 divisors (see below), whose sum is σ = 26044935696. Its totient is φ = 16800368400.

The previous prime is 21002220409. The next prime is 21002220431. The reversal of 21002220425 is 52402220012.

It is not a de Polignac number, because 21002220425 - 2⁴ = 21002220409 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21002220397 and 21002220406.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 353090 + ... + 408260.

It is an arithmetic number, because the mean of its divisors is an integer number (2170411308).

Almost surely, 2^21002220425 is an apocalyptic number.

21002220425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

21002220425 is a deficient number, since it is larger than the sum of its proper divisors (5042715271).

21002220425 is a wasteful number, since it uses less digits than its factorization.

21002220425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70408 (or 70403 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

Adding to 21002220425 its reverse (52402220012), we get a palindrome (73404440437).

The spelling of 21002220425 in words is "twenty-one billion, two million, two hundred twenty thousand, four hundred twenty-five".