1017897720 has 128 divisors (see below), whose sum is σ = 3571223040. Its totient is φ = 227243520.

The previous prime is 1017897719. The next prime is 1017897721. The reversal of 1017897720 is 277987101.

It is an interprime number because it is at equal distance from previous prime (1017897719) and next prime (1017897721).

It is a super-2 number, since 2×1017897720² = 2072231536762396800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1017897721) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 22030 + ... + 50210.

It is an arithmetic number, because the mean of its divisors is an integer number (27900180).

Almost surely, 2^1017897720 is an apocalyptic number.

1017897720 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 1017897720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1785611520).

1017897720 is an abundant number, since it is smaller than the sum of its proper divisors (2553325320).

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

1017897720 is a wasteful number, since it uses less digits than its factorization.

1017897720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28245 (or 28241 counting only the distinct ones).

The product of its (nonzero) digits is 49392, while the sum is 42.

The square root of 1017897720 is about 31904.5093991429. The cubic root of 1017897720 is about 1005.9306643543.

The spelling of 1017897720 in words is "one billion, seventeen million, eight hundred ninety-seven thousand, seven hundred twenty".