61820401 has 4 divisors (see below), whose sum is σ = 61875172. Its totient is φ = 61765632.

The previous prime is 61820399. The next prime is 61820453. The reversal of 61820401 is 10402816.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 56175025 + 5645376 = 7495^2 + 2376^2 .

It is a cyclic number.

It is not a de Polignac number, because 61820401 - 2¹ = 61820399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61820491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25656 + ... + 27961.

It is an arithmetic number, because the mean of its divisors is an integer number (15468793).

Almost surely, 2^61820401 is an apocalyptic number.

It is an amenable number.

61820401 is a deficient number, since it is larger than the sum of its proper divisors (54771).

61820401 is a wasteful number, since it uses less digits than its factorization.

61820401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 54770.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 61820401 is about 7862.5950550693. The cubic root of 61820401 is about 395.4066228752.

The spelling of 61820401 in words is "sixty-one million, eight hundred twenty thousand, four hundred one".