1171561620 has 48 divisors (see below), whose sum is σ = 3312868608. Its totient is φ = 309321600.

The previous prime is 1171561619. The next prime is 1171561631. The reversal of 1171561620 is 261651711.

It is a Harshad number since it is a multiple of its sum of digits (30).

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, 90604 + ... + 102723.

It is an arithmetic number, because the mean of its divisors is an integer number (69018096).

Almost surely, 2^1171561620 is an apocalyptic number.

1171561620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1171561620 is an abundant number, since it is smaller than the sum of its proper divisors (2141306988).

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

1171561620 is a wasteful number, since it uses less digits than its factorization.

1171561620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193440 (or 193438 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 30.

The square root of 1171561620 is about 34228.0823301569. The cubic root of 1171561620 is about 1054.1968446075.

Subtracting from 1171561620 its reverse (261651711), we obtain a palindrome (909909909).

The spelling of 1171561620 in words is "one billion, one hundred seventy-one million, five hundred sixty-one thousand, six hundred twenty".