21400522 has 16 divisors (see below), whose sum is σ = 37713312. Its totient is φ = 8979120.

The previous prime is 21400507. The next prime is 21400523. The reversal of 21400522 is 22500412.

It is a junction number, because it is equal to n+sod(n) for n = 21400496 and 21400505.

It is not an unprimeable number, because it can be changed into a prime (21400523) 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, 37128 + ... + 37699.

It is an arithmetic number, because the mean of its divisors is an integer number (2357082).

Almost surely, 2^21400522 is an apocalyptic number.

21400522 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21400522 is a deficient number, since it is larger than the sum of its proper divisors (16312790).

21400522 is a wasteful number, since it uses less digits than its factorization.

21400522 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74853.

The product of its (nonzero) digits is 160, while the sum is 16.

The square root of 21400522 is about 4626.0698222141. The cubic root of 21400522 is about 277.6353672269.

Adding to 21400522 its reverse (22500412), we get a palindrome (43900934).

The spelling of 21400522 in words is "twenty-one million, four hundred thousand, five hundred twenty-two".