21225583979 has 2 divisors, whose sum is σ = 21225583980. Its totient is φ = 21225583978.

The previous prime is 21225583963. The next prime is 21225584053. The reversal of 21225583979 is 97938552212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21225583979 - 2⁴ = 21225583963 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21225583979.

It is not a weakly prime, because it can be changed into another prime (21225583919) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10612791989 + 10612791990.

It is an arithmetic number, because the mean of its divisors is an integer number (10612791990).

Almost surely, 2^21225583979 is an apocalyptic number.

21225583979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21225583979 is an equidigital number, since it uses as much as digits as its factorization.

21225583979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2721600, while the sum is 53.

The spelling of 21225583979 in words is "twenty-one billion, two hundred twenty-five million, five hundred eighty-three thousand, nine hundred seventy-nine".