21437378506 has 8 divisors (see below), whose sum is σ = 32157118944. Its totient is φ = 10718338860.

The previous prime is 21437378483. The next prime is 21437378507. The reversal of 21437378506 is 60587373412.

It is a happy number.

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

It is a super-2 number, since 2×21437378506² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21437378507) 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, 90540 + ... + 225991.

It is an arithmetic number, because the mean of its divisors is an integer number (4019639868).

Almost surely, 2^21437378506 is an apocalyptic number.

21437378506 is a deficient number, since it is larger than the sum of its proper divisors (10719740438).

21437378506 is a wasteful number, since it uses less digits than its factorization.

21437378506 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 350396.

The product of its (nonzero) digits is 846720, while the sum is 46.

The spelling of 21437378506 in words is "twenty-one billion, four hundred thirty-seven million, three hundred seventy-eight thousand, five hundred six".