21150206312440 has 64 divisors (see below), whose sum is σ = 48839156926560. Its totient is φ = 8238815907840.

The previous prime is 21150206312429. The next prime is 21150206312441. The reversal of 21150206312440 is 4421360205112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21150206312441) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17664621 + ... + 18823900.

Almost surely, 2^{21150206312440} is an apocalyptic number.

21150206312440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21150206312440 is an abundant number, since it is smaller than the sum of its proper divisors (27688950614120).

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

21150206312440 is a wasteful number, since it uses less digits than its factorization.

21150206312440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36488912 (or 36488908 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

Adding to 21150206312440 its reverse (4421360205112), we get a palindrome (25571566517552).

The spelling of 21150206312440 in words is "twenty-one trillion, one hundred fifty billion, two hundred six million, three hundred twelve thousand, four hundred forty".