21554350213 has 4 divisors (see below), whose sum is σ = 23513836608. Its totient is φ = 19594863820.

The previous prime is 21554350193. The next prime is 21554350229. The reversal of 21554350213 is 31205345512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21554350213 - 2⁹ = 21554349701 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21554380213) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 979743181 + ... + 979743202.

It is an arithmetic number, because the mean of its divisors is an integer number (5878459152).

Almost surely, 2^21554350213 is an apocalyptic number.

It is an amenable number.

21554350213 is a deficient number, since it is larger than the sum of its proper divisors (1959486395).

21554350213 is a wasteful number, since it uses less digits than its factorization.

21554350213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1959486394.

The product of its (nonzero) digits is 18000, while the sum is 31.

Adding to 21554350213 its reverse (31205345512), we get a palindrome (52759695725).

The spelling of 21554350213 in words is "twenty-one billion, five hundred fifty-four million, three hundred fifty thousand, two hundred thirteen".