821420138 has 16 divisors (see below), whose sum is σ = 1536162624. Its totient is φ = 320033760.

The previous prime is 821420123. The next prime is 821420143. The reversal of 821420138 is 831024128.

821420138 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×821420138² = 1349462086223878088, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 821420138.

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, 2666795 + ... + 2667102.

It is an arithmetic number, because the mean of its divisors is an integer number (96010164).

Almost surely, 2^821420138 is an apocalyptic number.

821420138 is a deficient number, since it is larger than the sum of its proper divisors (714742486).

821420138 is a wasteful number, since it uses less digits than its factorization.

821420138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5333917.

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 821420138 is about 28660.4280847303. The cubic root of 821420138 is about 936.5301901913.

The spelling of 821420138 in words is "eight hundred twenty-one million, four hundred twenty thousand, one hundred thirty-eight".