1955211720 has 768 divisors, whose sum is σ = 8234265600. Its totient is φ = 365783040.

The previous prime is 1955211691. The next prime is 1955211721. The reversal of 1955211720 is 271125591.

It is a super-4 number, since 4×1955211720⁴ (a number of 38 digits) contains 4444 as substring.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1955211721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 45470019 + ... + 45470061.

It is an arithmetic number, because the mean of its divisors is an integer number (10721700).

Almost surely, 2^1955211720 is an apocalyptic number.

1955211720 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 1955211720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4117132800).

1955211720 is an abundant number, since it is smaller than the sum of its proper divisors (6279053880).

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

1955211720 is a wasteful number, since it uses less digits than its factorization.

1955211720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 127 counting only the distinct ones).

The product of its (nonzero) digits is 6300, while the sum is 33.

The square root of 1955211720 is about 44217.7760634793. The cubic root of 1955211720 is about 1250.4450084885.

The spelling of 1955211720 in words is "one billion, nine hundred fifty-five million, two hundred eleven thousand, seven hundred twenty".