61881819 has 16 divisors (see below), whose sum is σ = 87623712. Its totient is φ = 38711808.

The previous prime is 61881779. The next prime is 61881821. The reversal of 61881819 is 91818816.

It is not a de Polignac number, because 61881819 - 2¹³ = 61873627 is a prime.

It is a super-2 number, since 2×61881819² = 7658719045497522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (61881319) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17397 + ... + 20649.

It is an arithmetic number, because the mean of its divisors is an integer number (5476482).

Almost surely, 2^61881819 is an apocalyptic number.

61881819 is a deficient number, since it is larger than the sum of its proper divisors (25741893).

61881819 is a wasteful number, since it uses less digits than its factorization.

61881819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3646.

The product of its digits is 27648, while the sum is 42.

The square root of 61881819 is about 7866.4997934278. The cubic root of 61881819 is about 395.5375238166.

The spelling of 61881819 in words is "sixty-one million, eight hundred eighty-one thousand, eight hundred nineteen".