21554633407 has 2 divisors, whose sum is σ = 21554633408. Its totient is φ = 21554633406.

The previous prime is 21554633393. The next prime is 21554633411. The reversal of 21554633407 is 70433645512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21554633407 - 2⁷ = 21554633279 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21554633407.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21554633417) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10777316703 + 10777316704.

It is an arithmetic number, because the mean of its divisors is an integer number (10777316704).

Almost surely, 2^21554633407 is an apocalyptic number.

21554633407 is a deficient number, since it is larger than the sum of its proper divisors (1).

21554633407 is an equidigital number, since it uses as much as digits as its factorization.

21554633407 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 302400, while the sum is 40.

The spelling of 21554633407 in words is "twenty-one billion, five hundred fifty-four million, six hundred thirty-three thousand, four hundred seven".