21651212034 has 24 divisors (see below), whose sum is σ = 48648403440. Its totient is φ = 7217070516.

The previous prime is 21651212029. The next prime is 21651212047. The reversal of 21651212034 is 43021215612.

21651212034 is a `hidden beast` number, since 2 + 1 + 651 + 2 + 1 + 2 + 0 + 3 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 21651211989 and 21651212007.

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, 22274424 + ... + 22275395.

It is an arithmetic number, because the mean of its divisors is an integer number (2027016810).

Almost surely, 2^21651212034 is an apocalyptic number.

21651212034 is an abundant number, since it is smaller than the sum of its proper divisors (26997191406).

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

21651212034 is an equidigital number, since it uses as much as digits as its factorization.

21651212034 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44549836 (or 44549824 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

Adding to 21651212034 its reverse (43021215612), we get a palindrome (64672427646).

The spelling of 21651212034 in words is "twenty-one billion, six hundred fifty-one million, two hundred twelve thousand, thirty-four".