21025023311 has 4 divisors (see below), whose sum is σ = 21166131000. Its totient is φ = 20883915624.

The previous prime is 21025023277. The next prime is 21025023353. The reversal of 21025023311 is 11332052012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21025023311 - 2¹⁸ = 21024761167 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 (21025023361) 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 in 3 ways as a sum of consecutive naturals, for example, 70553621 + ... + 70553918.

It is an arithmetic number, because the mean of its divisors is an integer number (5291532750).

Almost surely, 2^21025023311 is an apocalyptic number.

21025023311 is a deficient number, since it is larger than the sum of its proper divisors (141107689).

21025023311 is a wasteful number, since it uses less digits than its factorization.

21025023311 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141107688.

The product of its (nonzero) digits is 360, while the sum is 20.

Adding to 21025023311 its reverse (11332052012), we get a palindrome (32357075323).

The spelling of 21025023311 in words is "twenty-one billion, twenty-five million, twenty-three thousand, three hundred eleven".