21145354506 has 16 divisors (see below), whose sum is σ = 46989676800. Its totient is φ = 7048451484.

The previous prime is 21145354499. The next prime is 21145354507. The reversal of 21145354506 is 60545354112.

21145354506 is a `hidden beast` number, since 2 + 1 + 145 + 3 + 5 + 4 + 506 = 666.

It is not an unprimeable number, because it can be changed into a prime (21145354507) 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, 195790266 + ... + 195790373.

It is an arithmetic number, because the mean of its divisors is an integer number (2936854800).

Almost surely, 2^21145354506 is an apocalyptic number.

21145354506 is an abundant number, since it is smaller than the sum of its proper divisors (25844322294).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21145354506 is a wasteful number, since it uses less digits than its factorization.

21145354506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391580650 (or 391580644 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 21145354506 in words is "twenty-one billion, one hundred forty-five million, three hundred fifty-four thousand, five hundred six".