20111954940 has 720 divisors, whose sum is σ = 82758703104. Its totient is φ = 4038854400.

The previous prime is 20111954903. The next prime is 20111954977. The reversal of 20111954940 is 4945911102.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20111954903) and next prime (20111954977).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 20111954895 and 20111954904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 27068209 + ... + 27068951.

Almost surely, 2^20111954940 is an apocalyptic number.

20111954940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20111954940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41379351552).

20111954940 is an abundant number, since it is smaller than the sum of its proper divisors (62646748164).

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

20111954940 is a wasteful number, since it uses less digits than its factorization.

20111954940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 820 (or 802 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 36.

The spelling of 20111954940 in words is "twenty billion, one hundred eleven million, nine hundred fifty-four thousand, nine hundred forty".