21420015642474 has 16 divisors (see below), whose sum is σ = 43884910097280. Its totient is φ = 6965858745440.

The previous prime is 21420015642457. The next prime is 21420015642491. The reversal of 21420015642474 is 47424651002412.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21420015642457) and next prime (21420015642491).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 43536616914 + ... + 43536617405.

It is an arithmetic number, because the mean of its divisors is an integer number (2742806881080).

Almost surely, 2^{21420015642474} is an apocalyptic number.

21420015642474 is an abundant number, since it is smaller than the sum of its proper divisors (22464894454806).

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

21420015642474 is a wasteful number, since it uses less digits than its factorization.

21420015642474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87073234365.

The product of its (nonzero) digits is 430080, while the sum is 42.

Adding to 21420015642474 its reverse (47424651002412), we get a palindrome (68844666644886).

The spelling of 21420015642474 in words is "twenty-one trillion, four hundred twenty billion, fifteen million, six hundred forty-two thousand, four hundred seventy-four".