21232121630 has 16 divisors (see below), whose sum is σ = 38496783600. Its totient is φ = 8430856512.

The previous prime is 21232121623. The next prime is 21232121639. The reversal of 21232121630 is 3612123212.

It is a super-2 number, since 2×21232121630² (a number of 21 digits) contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a junction number, because it is equal to n+sod(n) for n = 21232121596 and 21232121605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21232121639) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7747580 + ... + 7750319.

It is an arithmetic number, because the mean of its divisors is an integer number (2406048975).

Almost surely, 2^21232121630 is an apocalyptic number.

21232121630 is a deficient number, since it is larger than the sum of its proper divisors (17264661970).

21232121630 is a wasteful number, since it uses less digits than its factorization.

21232121630 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15498043.

The product of its (nonzero) digits is 864, while the sum is 23.

Adding to 21232121630 its reverse (3612123212), we get a palindrome (24844244842).

The spelling of 21232121630 in words is "twenty-one billion, two hundred thirty-two million, one hundred twenty-one thousand, six hundred thirty".