1956821061 has 16 divisors (see below), whose sum is σ = 2838766784. Its totient is φ = 1191780864.

The previous prime is 1956821059. The next prime is 1956821129. The reversal of 1956821061 is 1601286591.

It is not a de Polignac number, because 1956821061 - 2¹ = 1956821059 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1956821021) 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, 254851 + ... + 262416.

It is an arithmetic number, because the mean of its divisors is an integer number (177422924).

Almost surely, 2^1956821061 is an apocalyptic number.

It is an amenable number.

1956821061 is a deficient number, since it is larger than the sum of its proper divisors (881945723).

1956821061 is a wasteful number, since it uses less digits than its factorization.

1956821061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 517380.

The product of its (nonzero) digits is 25920, while the sum is 39.

The square root of 1956821061 is about 44235.9702165557. The cubic root of 1956821061 is about 1250.7879961586.

The spelling of 1956821061 in words is "one billion, nine hundred fifty-six million, eight hundred twenty-one thousand, sixty-one".