1020123720 has 768 divisors, whose sum is σ = 4528742400. Its totient is φ = 200309760.

The previous prime is 1020123677. The next prime is 1020123739. The reversal of 1020123720 is 273210201.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1020123693 and 1020123702.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 21704737 + ... + 21704783.

It is an arithmetic number, because the mean of its divisors is an integer number (5896800).

Almost surely, 2^1020123720 is an apocalyptic number.

1020123720 is a gapful number since it is divisible by the number (10) 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 1020123720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2264371200).

1020123720 is an abundant number, since it is smaller than the sum of its proper divisors (3508618680).

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

1020123720 is a wasteful number, since it uses less digits than its factorization.

1020123720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120 (or 104 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 1020123720 is about 31939.3756983445. The cubic root of 1020123720 is about 1006.6634070525.

Adding to 1020123720 its reverse (273210201), we get a palindrome (1293333921).

The spelling of 1020123720 in words is "one billion, twenty million, one hundred twenty-three thousand, seven hundred twenty".