21354510501 has 24 divisors (see below), whose sum is σ = 31058586104. Its totient is φ = 14138167680.

The previous prime is 21354510473. The next prime is 21354510553. The reversal of 21354510501 is 10501545312.

21354510501 is a `hidden beast` number, since 2 + 13 + 545 + 105 + 0 + 1 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1936088001 + 19418422500 = 44001^2 + 139350^2 .

It is not a de Polignac number, because 21354510501 - 2⁵ = 21354510469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21354510581) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1224495 + ... + 1241811.

Almost surely, 2^21354510501 is an apocalyptic number.

It is an amenable number.

21354510501 is a deficient number, since it is larger than the sum of its proper divisors (9704075603).

21354510501 is a wasteful number, since it uses less digits than its factorization.

21354510501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18261 (or 18258 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 27.

The spelling of 21354510501 in words is "twenty-one billion, three hundred fifty-four million, five hundred ten thousand, five hundred one".