19900061 has 4 divisors (see below), whose sum is σ = 20586300. Its totient is φ = 19213824.

The previous prime is 19900057. The next prime is 19900123. The reversal of 19900061 is 16000991.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16000991 = 31 ⋅516161.

It can be written as a sum of positive squares in 2 ways, for example, as 16728100 + 3171961 = 4090^2 + 1781^2 .

It is a cyclic number.

It is not a de Polignac number, because 19900061 - 2² = 19900057 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19900061.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19900261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 343076 + ... + 343133.

It is an arithmetic number, because the mean of its divisors is an integer number (5146575).

Almost surely, 2^19900061 is an apocalyptic number.

It is an amenable number.

19900061 is a deficient number, since it is larger than the sum of its proper divisors (686239).

19900061 is an equidigital number, since it uses as much as digits as its factorization.

19900061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 686238.

The product of its (nonzero) digits is 486, while the sum is 26.

The square root of 19900061 is about 4460.9484417554. The cubic root of 19900061 is about 270.9888795063.

The spelling of 19900061 in words is "nineteen million, nine hundred thousand, sixty-one".