61021801 has 2 divisors, whose sum is σ = 61021802. Its totient is φ = 61021800.

The previous prime is 61021799. The next prime is 61021811. The reversal of 61021801 is 10812016.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 39677401 + 21344400 = 6299^2 + 4620^2 .

It is a cyclic number.

It is not a de Polignac number, because 61021801 - 2¹ = 61021799 is a prime.

Together with 61021799, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (61021811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30510900 + 30510901.

It is an arithmetic number, because the mean of its divisors is an integer number (30510901).

Almost surely, 2^61021801 is an apocalyptic number.

61021801 is the 4176-th centered heptagonal number.

It is an amenable number.

61021801 is a deficient number, since it is larger than the sum of its proper divisors (1).

61021801 is an equidigital number, since it uses as much as digits as its factorization.

61021801 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 19.

The square root of 61021801 is about 7811.6452172382. The cubic root of 61021801 is about 393.6966086672.

Adding to 61021801 its reverse (10812016), we get a palindrome (71833817).

The spelling of 61021801 in words is "sixty-one million, twenty-one thousand, eight hundred one".