1955497561 has 4 divisors (see below), whose sum is σ = 1955644324. Its totient is φ = 1955350800.

The previous prime is 1955497543. The next prime is 1955497567. The reversal of 1955497561 is 1657945591.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 736091161 + 1219406400 = 27131^2 + 34920^2 .

It is a cyclic number.

It is not a de Polignac number, because 1955497561 - 2⁷ = 1955497433 is a prime.

It is a super-2 number, since 2×1955497561² = 7647941422153897442, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1955497499 and 1955497508.

It is not an unprimeable number, because it can be changed into a prime (1955497567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51150 + ... + 80791.

It is an arithmetic number, because the mean of its divisors is an integer number (488911081).

Almost surely, 2^1955497561 is an apocalyptic number.

It is an amenable number.

1955497561 is a deficient number, since it is larger than the sum of its proper divisors (146763).

1955497561 is a wasteful number, since it uses less digits than its factorization.

1955497561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146762.

The product of its digits is 1701000, while the sum is 52.

The square root of 1955497561 is about 44221.0081409278. The cubic root of 1955497561 is about 1250.5059415376.

The spelling of 1955497561 in words is "one billion, nine hundred fifty-five million, four hundred ninety-seven thousand, five hundred sixty-one".