21150454440 has 64 divisors (see below), whose sum is σ = 64079631360. Its totient is φ = 5584275200.

The previous prime is 21150454433. The next prime is 21150454441. The reversal of 21150454440 is 4445405112.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21150454398 and 21150454407.

It is not an unprimeable number, because it can be changed into a prime (21150454441) 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, 860424 + ... + 884663.

It is an arithmetic number, because the mean of its divisors is an integer number (1001244240).

Almost surely, 2^21150454440 is an apocalyptic number.

21150454440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21150454440 is an abundant number, since it is smaller than the sum of its proper divisors (42929176920).

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

21150454440 is a wasteful number, since it uses less digits than its factorization.

21150454440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1745202 (or 1745198 counting only the distinct ones).

The product of its (nonzero) digits is 12800, while the sum is 30.

Adding to 21150454440 its reverse (4445405112), we get a palindrome (25595859552).

The spelling of 21150454440 in words is "twenty-one billion, one hundred fifty million, four hundred fifty-four thousand, four hundred forty".