20154961 has 2 divisors, whose sum is σ = 20154962. Its totient is φ = 20154960.

The previous prime is 20154941. The next prime is 20155021. The reversal of 20154961 is 16945102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10112400 + 10042561 = 3180^2 + 3169^2 .

It is a cyclic number.

It is not a de Polignac number, because 20154961 - 2⁷ = 20154833 is a prime.

It is not a weakly prime, because it can be changed into another prime (20154941) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10077480 + 10077481.

It is an arithmetic number, because the mean of its divisors is an integer number (10077481).

Almost surely, 2^20154961 is an apocalyptic number.

It is an amenable number.

20154961 is a deficient number, since it is larger than the sum of its proper divisors (1).

20154961 is an equidigital number, since it uses as much as digits as its factorization.

20154961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2160, while the sum is 28.

The square root of 20154961 is about 4489.4276918111. The cubic root of 20154961 is about 272.1410069416.

It can be divided in two parts, 20154 and 961, that added together give a triangular number (21115 = T₂₀₅).

The spelling of 20154961 in words is "twenty million, one hundred fifty-four thousand, nine hundred sixty-one".