21003012740 has 48 divisors (see below), whose sum is σ = 45556245504. Its totient is φ = 8125353600.

The previous prime is 21003012739. The next prime is 21003012743. The reversal of 21003012740 is 4721030012.

It is a super-2 number, since 2×21003012740² (a number of 21 digits) contains 22 as substring.

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

It is not an unprimeable number, because it can be changed into a prime (21003012743) 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, 1135970 + ... + 1154310.

It is an arithmetic number, because the mean of its divisors is an integer number (949088448).

Almost surely, 2^21003012740 is an apocalyptic number.

21003012740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21003012740 is an abundant number, since it is smaller than the sum of its proper divisors (24553232764).

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

21003012740 is a wasteful number, since it uses less digits than its factorization.

21003012740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20228 (or 20226 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 20.

Adding to 21003012740 its reverse (4721030012), we get a palindrome (25724042752).

The spelling of 21003012740 in words is "twenty-one billion, three million, twelve thousand, seven hundred forty".