21555054467 has 2 divisors, whose sum is σ = 21555054468. Its totient is φ = 21555054466.

The previous prime is 21555054427. The next prime is 21555054497. The reversal of 21555054467 is 76445055512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21555054467 - 2¹⁸ = 21554792323 is a prime.

It is not a weakly prime, because it can be changed into another prime (21555054427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10777527233 + 10777527234.

It is an arithmetic number, because the mean of its divisors is an integer number (10777527234).

Almost surely, 2^21555054467 is an apocalyptic number.

21555054467 is a deficient number, since it is larger than the sum of its proper divisors (1).

21555054467 is an equidigital number, since it uses as much as digits as its factorization.

21555054467 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 840000, while the sum is 44.

The spelling of 21555054467 in words is "twenty-one billion, five hundred fifty-five million, fifty-four thousand, four hundred sixty-seven".