1951561 has 2 divisors, whose sum is σ = 1951562. Its totient is φ = 1951560.

The previous prime is 1951553. The next prime is 1951591. The reversal of 1951561 is 1651591.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1279161 + 672400 = 1131^2 + 820^2 .

It is an emirp because it is prime and its reverse (1651591) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1951561 - 2³ = 1951553 is a prime.

1951561 is a lucky number.

It is a nialpdrome in base 5.

It is not a weakly prime, because it can be changed into another prime (1951501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 975780 + 975781.

It is an arithmetic number, because the mean of its divisors is an integer number (975781).

2^1951561 is an apocalyptic number.

It is an amenable number.

1951561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1951561 is an equidigital number, since it uses as much as digits as its factorization.

1951561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1350, while the sum is 28.

The square root of 1951561 is about 1396.9828202236. The cubic root of 1951561 is about 124.9666257567.

The spelling of 1951561 in words is "one million, nine hundred fifty-one thousand, five hundred sixty-one".