21451340502 has 24 divisors (see below), whose sum is σ = 46503359760. Its totient is φ = 7146530640.

The previous prime is 21451340479. The next prime is 21451340527. The reversal of 21451340502 is 20504315412.

21451340502 is a `hidden beast` number, since 2 + 145 + 13 + 4 + 0 + 502 = 666.

It is a super-2 number, since 2×21451340502² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 292477 + ... + 358392.

It is an arithmetic number, because the mean of its divisors is an integer number (1937639990).

Almost surely, 2^21451340502 is an apocalyptic number.

21451340502 is an abundant number, since it is smaller than the sum of its proper divisors (25052019258).

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

21451340502 is a wasteful number, since it uses less digits than its factorization.

21451340502 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652708 (or 652705 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 21451340502 its reverse (20504315412), we get a palindrome (41955655914).

The spelling of 21451340502 in words is "twenty-one billion, four hundred fifty-one million, three hundred forty thousand, five hundred two".