21153250409 has 2 divisors, whose sum is σ = 21153250410. Its totient is φ = 21153250408.

The previous prime is 21153250387. The next prime is 21153250507. The reversal of 21153250409 is 90405235112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10952250409 + 10201000000 = 104653^2 + 101000^2 .

It is a cyclic number.

It is not a de Polignac number, because 21153250409 - 2¹² = 21153246313 is a prime.

It is not a weakly prime, because it can be changed into another prime (21153250109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10576625204 + 10576625205.

It is an arithmetic number, because the mean of its divisors is an integer number (10576625205).

Almost surely, 2^21153250409 is an apocalyptic number.

It is an amenable number.

21153250409 is a deficient number, since it is larger than the sum of its proper divisors (1).

21153250409 is an equidigital number, since it uses as much as digits as its factorization.

21153250409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10800, while the sum is 32.

The spelling of 21153250409 in words is "twenty-one billion, one hundred fifty-three million, two hundred fifty thousand, four hundred nine".