1956397640 has 16 divisors (see below), whose sum is σ = 4401894780. Its totient is φ = 782559040.

The previous prime is 1956397637. The next prime is 1956397657. The reversal of 1956397640 is 467936591.

It can be written as a sum of positive squares in 2 ways, for example, as 1814930404 + 141467236 = 42602^2 + 11894^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24454931 + ... + 24455010.

Almost surely, 2^1956397640 is an apocalyptic number.

1956397640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1956397640 is an abundant number, since it is smaller than the sum of its proper divisors (2445497140).

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

1956397640 is a wasteful number, since it uses less digits than its factorization.

1956397640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48909952 (or 48909948 counting only the distinct ones).

The product of its (nonzero) digits is 1224720, while the sum is 50.

The square root of 1956397640 is about 44231.1840221353. The cubic root of 1956397640 is about 1250.6977736171.

The spelling of 1956397640 in words is "one billion, nine hundred fifty-six million, three hundred ninety-seven thousand, six hundred forty".