1802020861 has 2 divisors, whose sum is σ = 1802020862. Its totient is φ = 1802020860.

The previous prime is 1802020799. The next prime is 1802020867. The reversal of 1802020861 is 1680202081.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1562699961 + 239320900 = 39531^2 + 15470^2 .

It is a cyclic number.

It is not a de Polignac number, because 1802020861 - 2¹³ = 1802012669 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1802020867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 901010430 + 901010431.

It is an arithmetic number, because the mean of its divisors is an integer number (901010431).

Almost surely, 2^1802020861 is an apocalyptic number.

It is an amenable number.

1802020861 is a deficient number, since it is larger than the sum of its proper divisors (1).

1802020861 is an equidigital number, since it uses as much as digits as its factorization.

1802020861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1536, while the sum is 28.

The square root of 1802020861 is about 42450.2162656446. The cubic root of 1802020861 is about 1216.8954616281.

The spelling of 1802020861 in words is "one billion, eight hundred two million, twenty thousand, eight hundred sixty-one".