21001144340 has 24 divisors (see below), whose sum is σ = 48111712992. Its totient is φ = 7636779680.

The previous prime is 21001144337. The next prime is 21001144363. The reversal of 21001144340 is 4344110012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47729654 + ... + 47730093.

It is an arithmetic number, because the mean of its divisors is an integer number (2004654708).

Almost surely, 2^21001144340 is an apocalyptic number.

21001144340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21001144340 is an abundant number, since it is smaller than the sum of its proper divisors (27110568652).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21001144340 is a wasteful number, since it uses less digits than its factorization.

21001144340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95459767 (or 95459765 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

Adding to 21001144340 its reverse (4344110012), we get a palindrome (25345254352).

The spelling of 21001144340 in words is "twenty-one billion, one million, one hundred forty-four thousand, three hundred forty".