21030121040 has 40 divisors (see below), whose sum is σ = 49040183400. Its totient is φ = 8387076096.

The previous prime is 21030121037. The next prime is 21030121067. The reversal of 21030121040 is 4012103012.

It can be written as a sum of positive squares in 4 ways, for example, as 56130064 + 20973990976 = 7492^2 + 144824^2 .

It is a tau number, because it is divible by the number of its divisors (40).

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, 363065 + ... + 416984.

It is an arithmetic number, because the mean of its divisors is an integer number (1226004585).

Almost surely, 2^21030121040 is an apocalyptic number.

21030121040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21030121040 is an abundant number, since it is smaller than the sum of its proper divisors (28010062360).

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

21030121040 is a wasteful number, since it uses less digits than its factorization.

21030121040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780399 (or 780393 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 14.

Adding to 21030121040 its reverse (4012103012), we get a palindrome (25042224052).

The spelling of 21030121040 in words is "twenty-one billion, thirty million, one hundred twenty-one thousand, forty".