19780077 has 16 divisors (see below), whose sum is σ = 27744768. Its totient is φ = 12517440.

The previous prime is 19780073. The next prime is 19780087. The reversal of 19780077 is 77008791.

It is a happy number.

It is not a de Polignac number, because 19780077 - 2² = 19780073 is a prime.

It is a super-2 number, since 2×19780077² = 782502892251858, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19780073) 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, 2923 + ... + 6935.

It is an arithmetic number, because the mean of its divisors is an integer number (1734048).

Almost surely, 2^19780077 is an apocalyptic number.

It is an amenable number.

19780077 is a deficient number, since it is larger than the sum of its proper divisors (7964691).

19780077 is a wasteful number, since it uses less digits than its factorization.

19780077 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4100.

The product of its (nonzero) digits is 24696, while the sum is 39.

The square root of 19780077 is about 4447.4798481837. The cubic root of 19780077 is about 270.4431542777.

The spelling of 19780077 in words is "nineteen million, seven hundred eighty thousand, seventy-seven".