21211004040 has 128 divisors (see below), whose sum is σ = 67716000000. Its totient is φ = 5296693248.

The previous prime is 21211004029. The next prime is 21211004051. The reversal of 21211004040 is 4040011212.

It is an interprime number because it is at equal distance from previous prime (21211004029) and next prime (21211004051).

It is a Harshad number since it is a multiple of its sum of digits (15).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 379836 + ... + 432084.

It is an arithmetic number, because the mean of its divisors is an integer number (529031250).

Almost surely, 2^21211004040 is an apocalyptic number.

21211004040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21211004040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33858000000).

21211004040 is an abundant number, since it is smaller than the sum of its proper divisors (46504995960).

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

21211004040 is a wasteful number, since it uses less digits than its factorization.

21211004040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52479 (or 52475 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 15.

Adding to 21211004040 its reverse (4040011212), we get a palindrome (25251015252).

The spelling of 21211004040 in words is "twenty-one billion, two hundred eleven million, four thousand, forty".