21506206001542 has 8 divisors (see below), whose sum is σ = 33371698968000. Its totient is φ = 10382306345544.

The previous prime is 21506206001507. The next prime is 21506206001543. The reversal of 21506206001542 is 24510060260512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×21506206001542² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21506206001498 and 21506206001507.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21506206001543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 185398327542 + ... + 185398327657.

It is an arithmetic number, because the mean of its divisors is an integer number (4171462371000).

Almost surely, 2^{21506206001542} is an apocalyptic number.

21506206001542 is a deficient number, since it is larger than the sum of its proper divisors (11865492966458).

21506206001542 is a wasteful number, since it uses less digits than its factorization.

21506206001542 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370796655230.

The product of its (nonzero) digits is 28800, while the sum is 34.

The spelling of 21506206001542 in words is "twenty-one trillion, five hundred six billion, two hundred six million, one thousand, five hundred forty-two".