1278782901972 has 18 divisors (see below), whose sum is σ = 3232479002298. Its totient is φ = 426260967312.

The previous prime is 1278782901971. The next prime is 1278782901983. The reversal of 1278782901972 is 2791092878721.

1278782901972 is a `hidden beast` number, since 1 + 278 + 7 + 8 + 290 + 1 + 9 + 72 = 666.

It can be written as a sum of positive squares in only one way, i.e., 922187613636 + 356595288336 = 960306^2 + 597156^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×1278782901972² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1278782901971) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 17760873603 + ... + 17760873674.

Almost surely, 2^{1278782901972} is an apocalyptic number.

1278782901972 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

1278782901972 is an abundant number, since it is smaller than the sum of its proper divisors (1953696100326).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1278782901972 is a wasteful number, since it uses less digits than its factorization.

1278782901972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35521747287 (or 35521747282 counting only the distinct ones).

The product of its (nonzero) digits is 14224896, while the sum is 63.

The spelling of 1278782901972 in words is "one trillion, two hundred seventy-eight billion, seven hundred eighty-two million, nine hundred one thousand, nine hundred seventy-two".