21351630619 has 4 divisors (see below), whose sum is σ = 23292687960. Its totient is φ = 19410573280.

The previous prime is 21351630617. The next prime is 21351630659. The reversal of 21351630619 is 91603615312.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21351630619 - 2¹ = 21351630617 is a prime.

It is a super-3 number, since 3×21351630619³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21351630617) 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, 970528654 + ... + 970528675.

It is an arithmetic number, because the mean of its divisors is an integer number (5823171990).

Almost surely, 2^21351630619 is an apocalyptic number.

21351630619 is a deficient number, since it is larger than the sum of its proper divisors (1941057341).

21351630619 is a wasteful number, since it uses less digits than its factorization.

21351630619 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1941057340.

The product of its (nonzero) digits is 29160, while the sum is 37.

The spelling of 21351630619 in words is "twenty-one billion, three hundred fifty-one million, six hundred thirty thousand, six hundred nineteen".