1954561649 has 2 divisors, whose sum is σ = 1954561650. Its totient is φ = 1954561648.

The previous prime is 1954561639. The next prime is 1954561657. The reversal of 1954561649 is 9461654591.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1941019249 + 13542400 = 44057^2 + 3680^2 .

It is an emirp because it is prime and its reverse (9461654591) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1954561649 is a prime.

It is a super-2 number, since 2×1954561649² = 7640622479483198402, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1954561597 and 1954561606.

It is not a weakly prime, because it can be changed into another prime (1954561619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 977280824 + 977280825.

It is an arithmetic number, because the mean of its divisors is an integer number (977280825).

Almost surely, 2^1954561649 is an apocalyptic number.

It is an amenable number.

1954561649 is a deficient number, since it is larger than the sum of its proper divisors (1).

1954561649 is an equidigital number, since it uses as much as digits as its factorization.

1954561649 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1166400, while the sum is 50.

The square root of 1954561649 is about 44210.4246643255. The cubic root of 1954561649 is about 1250.3064100042.

The spelling of 1954561649 in words is "one billion, nine hundred fifty-four million, five hundred sixty-one thousand, six hundred forty-nine".