21518150801 has 4 divisors (see below), whose sum is σ = 24592172352. Its totient is φ = 18444129252.

The previous prime is 21518150747. The next prime is 21518150803. The reversal of 21518150801 is 10805181512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21518150801 - 2¹⁸ = 21517888657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21518150803) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1537010765 + ... + 1537010778.

It is an arithmetic number, because the mean of its divisors is an integer number (6148043088).

Almost surely, 2^21518150801 is an apocalyptic number.

It is an amenable number.

21518150801 is a deficient number, since it is larger than the sum of its proper divisors (3074021551).

21518150801 is an equidigital number, since it uses as much as digits as its factorization.

21518150801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3074021550.

The product of its (nonzero) digits is 3200, while the sum is 32.

The spelling of 21518150801 in words is "twenty-one billion, five hundred eighteen million, one hundred fifty thousand, eight hundred one".