4021237687656 has 128 divisors (see below), whose sum is σ = 12106975104000. Its totient is φ = 1087282870272.

The previous prime is 4021237687601. The next prime is 4021237687673. The reversal of 4021237687656 is 6567867321204.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a junction number, because it is equal to n+sod(n) for n = 4021237687596 and 4021237687605.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2287335 + ... + 3643401.

It is an arithmetic number, because the mean of its divisors is an integer number (94585743000).

Almost surely, 2^{4021237687656} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 4021237687656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (6053487552000).

4021237687656 is an abundant number, since it is smaller than the sum of its proper divisors (8085737416344).

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

4021237687656 is a wasteful number, since it uses less digits than its factorization.

4021237687656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1357031 (or 1357027 counting only the distinct ones).

The product of its (nonzero) digits is 20321280, while the sum is 57.

The spelling of 4021237687656 in words is "four trillion, twenty-one billion, two hundred thirty-seven million, six hundred eighty-seven thousand, six hundred fifty-six".