21402351550 has 12 divisors (see below), whose sum is σ = 39808373976. Its totient is φ = 8560940600.

The previous prime is 21402351511. The next prime is 21402351559. The reversal of 21402351550 is 5515320412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21402351559) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 214023466 + ... + 214023565.

It is an arithmetic number, because the mean of its divisors is an integer number (3317364498).

Almost surely, 2^21402351550 is an apocalyptic number.

21402351550 is a deficient number, since it is larger than the sum of its proper divisors (18406022426).

21402351550 is a wasteful number, since it uses less digits than its factorization.

21402351550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428047043 (or 428047038 counting only the distinct ones).

The product of its (nonzero) digits is 6000, while the sum is 28.

Adding to 21402351550 its reverse (5515320412), we get a palindrome (26917671962).

The spelling of 21402351550 in words is "twenty-one billion, four hundred two million, three hundred fifty-one thousand, five hundred fifty".