21764301240 has 64 divisors (see below), whose sum is σ = 71228626560. Its totient is φ = 5276193920.

The previous prime is 21764301179. The next prime is 21764301257. The reversal of 21764301240 is 4210346712.

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 = 21764301198 and 21764301207.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8242734 + ... + 8245373.

It is an arithmetic number, because the mean of its divisors is an integer number (1112947290).

Almost surely, 2^21764301240 is an apocalyptic number.

21764301240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21764301240 is an abundant number, since it is smaller than the sum of its proper divisors (49464325320).

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

21764301240 is a wasteful number, since it uses less digits than its factorization.

21764301240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16488132 (or 16488128 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

Adding to 21764301240 its reverse (4210346712), we get a palindrome (25974647952).

The spelling of 21764301240 in words is "twenty-one billion, seven hundred sixty-four million, three hundred one thousand, two hundred forty".