1961428260099 has 128 divisors (see below), whose sum is σ = 3635525099520. Its totient is φ = 908146944000.

The previous prime is 1961428260049. The next prime is 1961428260119. The reversal of 1961428260099 is 9900628241691.

It is a Cunningham number, because it is equal to 1400510²-1.

It is not a de Polignac number, because 1961428260099 - 2¹³ = 1961428251907 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (1961428260049) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 292703449 + ... + 292710149.

It is an arithmetic number, because the mean of its divisors is an integer number (28402539840).

Almost surely, 2^{1961428260099} is an apocalyptic number.

1961428260099 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1961428260099 is a deficient number, since it is larger than the sum of its proper divisors (1674096839421).

1961428260099 is a wasteful number, since it uses less digits than its factorization.

1961428260099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10681.

The product of its (nonzero) digits is 3359232, while the sum is 57.

The spelling of 1961428260099 in words is "one trillion, nine hundred sixty-one billion, four hundred twenty-eight million, two hundred sixty thousand, ninety-nine".