21000278740 has 24 divisors (see below), whose sum is σ = 50400669312. Its totient is φ = 7200095520.

The previous prime is 21000278729. The next prime is 21000278753. The reversal of 21000278740 is 4787200012.

It is a super-3 number, since 3×21000278740³ (a number of 32 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75000856 + ... + 75001135.

It is an arithmetic number, because the mean of its divisors is an integer number (2100027888).

Almost surely, 2^21000278740 is an apocalyptic number.

21000278740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21000278740 is an abundant number, since it is smaller than the sum of its proper divisors (29400390572).

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

21000278740 is a wasteful number, since it uses less digits than its factorization.

21000278740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 150002007 (or 150002005 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 31.

Adding to 21000278740 its reverse (4787200012), we get a palindrome (25787478752).

The spelling of 21000278740 in words is "twenty-one billion, two hundred seventy-eight thousand, seven hundred forty".