20356671440 has 80 divisors (see below), whose sum is σ = 56937486720. Its totient is φ = 6612088320.

The previous prime is 20356671397. The next prime is 20356671469. The reversal of 20356671440 is 4417665302.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×20356671440² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (38).

It is a junction number, because it is equal to n+sod(n) for n = 20356671394 and 20356671403.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 945971 + ... + 967250.

It is an arithmetic number, because the mean of its divisors is an integer number (711718584).

Almost surely, 2^20356671440 is an apocalyptic number.

20356671440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20356671440 is an abundant number, since it is smaller than the sum of its proper divisors (36580815280).

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

20356671440 is a wasteful number, since it uses less digits than its factorization.

20356671440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1913260 (or 1913254 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 38.

The spelling of 20356671440 in words is "twenty billion, three hundred fifty-six million, six hundred seventy-one thousand, four hundred forty".