6777021638 has 16 divisors (see below), whose sum is σ = 10272788064. Its totient is φ = 3352934400.

The previous prime is 6777021613. The next prime is 6777021689. The reversal of 6777021638 is 8361207776.

It is a junction number, because it is equal to n+sod(n) for n = 6777021592 and 6777021601.

It is a congruent number.

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, 33956 + ... + 121272.

It is an arithmetic number, because the mean of its divisors is an integer number (642049254).

Almost surely, 2^6777021638 is an apocalyptic number.

6777021638 is a deficient number, since it is larger than the sum of its proper divisors (3495766426).

6777021638 is a wasteful number, since it uses less digits than its factorization.

6777021638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87727.

The product of its (nonzero) digits is 592704, while the sum is 47.

The square root of 6777021638 is about 82322.6678260611. The cubic root of 6777021638 is about 1892.4000786497.

The spelling of 6777021638 in words is "six billion, seven hundred seventy-seven million, twenty-one thousand, six hundred thirty-eight".