21040101651 has 16 divisors (see below), whose sum is σ = 28748472480. Its totient is φ = 13679489280.

The previous prime is 21040101587. The next prime is 21040101659. The reversal of 21040101651 is 15610104012.

It is not a de Polignac number, because 21040101651 - 2⁶ = 21040101587 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21040101659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 312381 + ... + 373713.

It is an arithmetic number, because the mean of its divisors is an integer number (1796779530).

Almost surely, 2^21040101651 is an apocalyptic number.

21040101651 is a deficient number, since it is larger than the sum of its proper divisors (7708370829).

21040101651 is a wasteful number, since it uses less digits than its factorization.

21040101651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64166.

The product of its (nonzero) digits is 240, while the sum is 21.

Adding to 21040101651 its reverse (15610104012), we get a palindrome (36650205663).

The spelling of 21040101651 in words is "twenty-one billion, forty million, one hundred one thousand, six hundred fifty-one".