21054522505 has 16 divisors (see below), whose sum is σ = 25357224960. Its totient is φ = 16782501568.

The previous prime is 21054522487. The next prime is 21054522539. The reversal of 21054522505 is 50522545012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21054522505 - 2¹¹ = 21054520457 is a prime.

It is a super-4 number, since 4×21054522505⁴ (a number of 42 digits) contains 4444 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2460264 + ... + 2468806.

It is an arithmetic number, because the mean of its divisors is an integer number (1584826560).

Almost surely, 2^21054522505 is an apocalyptic number.

It is an amenable number.

21054522505 is a deficient number, since it is larger than the sum of its proper divisors (4302702455).

21054522505 is a wasteful number, since it uses less digits than its factorization.

21054522505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10280.

The product of its (nonzero) digits is 20000, while the sum is 31.

The spelling of 21054522505 in words is "twenty-one billion, fifty-four million, five hundred twenty-two thousand, five hundred five".