20634619 has 2 divisors, whose sum is σ = 20634620. Its totient is φ = 20634618.

The previous prime is 20634613. The next prime is 20634643. The reversal of 20634619 is 91643602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20634619 - 2¹¹ = 20632571 is a prime.

It is a super-2 number, since 2×20634619² = 851575002550322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20634613) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10317309 + 10317310.

It is an arithmetic number, because the mean of its divisors is an integer number (10317310).

Almost surely, 2^20634619 is an apocalyptic number.

20634619 is a deficient number, since it is larger than the sum of its proper divisors (1).

20634619 is an equidigital number, since it uses as much as digits as its factorization.

20634619 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 20634619 is about 4542.5344247457. The cubic root of 20634619 is about 274.2829540092.

The spelling of 20634619 in words is "twenty million, six hundred thirty-four thousand, six hundred nineteen".