21225252254 has 4 divisors (see below), whose sum is σ = 31837878384. Its totient is φ = 10612626126.

The previous prime is 21225252253. The next prime is 21225252259. The reversal of 21225252254 is 45225252212.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×21225252254² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21225252254.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21225252253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5306313062 + ... + 5306313065.

It is an arithmetic number, because the mean of its divisors is an integer number (7959469596).

Almost surely, 2^21225252254 is an apocalyptic number.

21225252254 is a deficient number, since it is larger than the sum of its proper divisors (10612626130).

21225252254 is a wasteful number, since it uses less digits than its factorization.

21225252254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10612626129.

The product of its digits is 32000, while the sum is 32.

The spelling of 21225252254 in words is "twenty-one billion, two hundred twenty-five million, two hundred fifty-two thousand, two hundred fifty-four".